Hey guys I had my tech install a boost/vacuum gauge from Glowshift last week. My car has ran perfect for the past few years no issues at all. He hooked the gauge up per glow shifts instructions by running through the firewall hooking up to my boost vacuum line & getting power from a 12v source by hooking up through my fuse box under the hood. The 2nd he was done with the install I started my car & instantly I had my cel come on & my idle started going up & down my rpms were revving without touching the gas pedal. We turned my car off & hooked up the computer to see what codes were thrown. The install of this boost gauge threw 4 codes-P0069
P0121
P1101
P0068
My tech cleared the codes took it for a test spin & the cel came back on & it went into reduced engine power. My tech looked over the boost gauge install everything looked fine he cleared the codes again took it for another spin & everything seemed fine so I went on my way. Well over the past week after installing this boost gauge my cel has come back on & I continue to go into limp home mode almost everyday. When this happens of course I just pull over let the car sit for like 10 minutes & then I'm able to drive home but I don't get into boost to be safe. Today I took it back to my tech & had him unhook the gauge from my fuse box since we know it's the gauge that is causing this. The 2nd he disconnected the gauge from my fuse box my car got worse I tried to drive it home & I couldn't go more than 20 feet before going back into limp home mode. I had it towed to his shop which is where it's sitting now.

Any help that you guys could give me please do. Obviously this gauge messed something up in not sure if it shorted out something or fried something or what please help!!!!

 

Was the boost gauge wired in to ANY Throttle body or MAF wiring?

 

No I don't believe so he hooked it up the exact way that the Glowshift instructions had recommended which was a 12v source through the fuse box & I believe one wire went to the ignition source so that the gauge turns on & off when you start the car

 

did you tap into the correct vac line ? any pictures ? you could have a vac leak due to improper install.

I installed my without any issue at all. I tapped into the stock oem boost gauge harness though, i can even dim my gauge with the dimmer on the dash

 

Yes we tapped the right lines. So we found that my emissions fuse that we tapped into had blown & replaced that thinking it would fix the problem however when we took it out for a test spin it went right back into limp mode & the cel light came back on when attempting to shift into 2nd gear. My tech seems to think that this boost gauge shorted out my entire fuse box since its throwing 5v reference. He's going to look at it some more but again he's talking like I'm going to need an entire new fuse box for under the hood!!!!

 

can I be a jerk?

Seriously, how can anyone who is supposed to be considered a mechanic screw up a car by adding a gauge?

I get it if you don't know how to do it, have accepted your limitations, and get someone to do the install for you - but this sounds like a case of the blind leading the blind.

...

OK, now I'll be nice;

Put it back to stock, verify the problems are gone, then start over afresh, getting another mechanic's help.

 

I have to agree with soundjunky... Installing a boost guage is a very very simple task to do....

 

Specifically which Glowshift gauge did you have installed?

While I saw mostly mechanical boost gauges on their site, they do have ones with senders.

I'm kinda wondering if he didn't somehow wire into the GMLan wire that's in the stock boost gauge connector.

 

Sounds like a vac leak. Whats the gauge read at idle?

 

How did he get the wires through the firewall? Almost sounds like whatever he did he may have damaged a wire or 2. Or he hooked up the power wire to the wrong place. I'd like to see this install, take pics

 

Thanks for all the feedback guys this helps I'm devastated right now my car was perfect not a thing wrong with it I've dropped so many mods into it over the past two years & I was one down pipe & a cat back away from being complete. Any how below are some pics that I took after the boost gauge install however I can't take anymore because they have my car & because once I found out that this gauge had been what was causing my reduced engine power & codes I had him disconnect it from the fuse box & that's when things went from bad to worse. Unfortunately in these pics we can't see under the fuse box lid so I'm not sure what fuse he tapped into however I do know that we had the boost vacuum line hooked up right & I also know that the boost gauge wire that needs a 12v continues power supply was hooked to my positive port on the fuse box under the hood where you would connect the positive end of your jumper cables to if you needed a jump. If you guys check out my other post on here over the past week they are all related to this same issue. You will see where at first I wasn't sure what was causing this stuff to happen but it didn't take long to figure out that it was from this dam boost gauge. Also once we had the boost gauge installed it still didn't work it was flashing so we looked at the back of the gauge & noticed that the wire harness that plugs into port D had a faulty loose connection. Even though we had it clicked into place it was still loose no matter how we put it in & the only way the gauge would work was by holding the wire into the back of the gauge with your finger or a piece of tape. I notified glow shift of this right away & they sent me a new wire harness however I just got it today & now that this crap is going on I don't need it since I will be sending them this gauge back & hiking up the OEM one that I just got from GMpartsdirect. Is it possible that this faulty wire harness could have caused this to happen ? My tech & his assistant that I use I've been going to for a couple of years now they both worked at our local GM dealer for over 20 years before opening up their own shop so between the two of them they have 40 years of experience with GMs. I really couldn't imagine that he installed it wrong he did exactly what the glow shift instructions said to do. I have included a screen shot of those instructions below. Today when I called the shop they thought they had fixed it he said that the fuse that he tapped into had popped out & wasn't making a connection so he got it back in cleared the codes & the car seemed fine. I was then on my way to go pick it up when he called back & said that he took it for a test spin & after shifting into 2nd gear it went back into limp mode & threw the codes again. That's when he said that he thinks this gauge may have caused a bigger problem & recommend that we may need to replace the entire fuse box! He said that he was going to spend the rest of today checking the other fuses & doing some research & that he would get back with me tomorrow to let me know.

If there's anything else that you guys can think of please let me know I mean if I have to drop $300 on a new fuse box plus labor I will if it means fixing my car but my fear is that I do all of that & the problem is still there. I just pray that it didn't effect my computer or anything.

I was a little confused with him thinking the entire fuse box needed replaced when I have been able to drive it for the past week with the boost gauge installed. I had a piece of tape holding the loose wire harness into the back of the gauge & the gauge worked fine & the boost & vacuum levels read correct as well. The only issue that I had over the past week was with the cel the intermittent idling issue the four codes that were thrown & the reduced engine power every few days which yes is a lot but I would think that if the entire fuse box needed replaced then how did all of my turn signals & headlights & fog lights & radio & everything else work if the fuse box was fried ? Also like I said before the above issues are the issues that I had the 2nd the boost gauge was installed however when I would get the reduced engine power every couple of days I would just pull over sit for about 10 min & then I was able to drive home without issues as long as I didn't get into boost.

The 2nd that I had him disconnect the boost gauge from the fuse box is when the symptoms became immediately worse ! I didn't get more than a half mile from his shop after he disconnected it before I went into limp mode & then after letting it sit for 10 min which always fixed it before I tried to go again & I went right back into limp mode & then again a third time no more than 50 feet down the rd which is when I had to drop $125 over the phone with AAA & have them tow my car back to him! My question is why did it get so much worse after disconnecting the boost gauge from the fuse box when the boost gauge is what was causing these issues ? I know he said today that the fuse that the gauge was hooked to had popped out & wasn't making a connection so I guess that's what could have done it but then after pushing that fuse back in & him taking it for a spin it went right back into limp mode so something isn't right here. We did check all of my vacuum lines & sensors they are all good & I don't see how it could be my throttle body when my throttle body was fine in fact like I said my car was perfect until this gauge was hooked up then the 2nd we started my car after hooking this dam thing up my car immediately started the idling issue where it kept revving up & down from like 1k to 2k rpm & the cel light came on & the codes were thrown so it has to be from this gauge & something within the fuse box.

 

 

Also just thought I would throw this in there in these pictures I did not have the vacuum line hooked up to the boost vacuum line yet however I was pointing to the boost vacuum line that we did tap into

 

Another important thing that I failed to mention here guys & I know it's a big one so I apologize for that I really thought that it could be the boost gauge install which is why I never mentioned this before anyhow at the same time of us doing the boost gauge install we also rebuilt my supercharger! We took it off & apart we greased the needle bearings down inside the case we also replaced both snout bearings we put in a new snout seal & added new sc oil. All parts were purchased from zzp. I'm starting to think that maybe this could have be caused by the sc rebuild maybe the sc gasket isn't on right or something. I also know from years ago any time I had the reduced engine power issue I would take it to the dealer & they would always replace the MAP sensor on top of the sc & that would always seem to fix the issue. I have been through 3-4 MAP sensors in the 8 years that I've owned the car so I wonder if a new MAP sensor would fix the issue here. I did go ahead & buy a new MAP sensor from zzp it just showed up in the mail yesterday so I'm going to have my tech put that on & see what happens here. Maybe it wasn't the gauge after all dam this is killing me I've been up all night for the past week and a half researching trying to find out what could be wrong here & the only thing I know is that it had to be something that was caused from either the boost gauge install or the sc rebuild. Any help you guys could give here would be great thanks

 

There is simply too much here to respond to.

My gut reaction is that they tapped something wrong and fried your fuse box.

If these guys were a truly stand up shop they would:
1) cover your tow
2) make your car right on their dime
Because they screwed it up.

I would recommend either taking it to a dealer, or another shop.

I believe the techII can diagnose your fuse box rather quickly;
One of my friends had his fuse box go bad, and after screwing with it for way too long, he sucked it up, and had it towed to a dealer where it was immediately (&properly) diagnosed, and fixed.

 

is the baro senser unplugged? did the throttle body get cleaned? the TB left unplugged after SC reinstallation?>

 

There is no way ur boost gauge install should cause any of this unless ur vac line is not connected right. All u have to wire it into is positive, and no not continuous positive, accessory power, u don't want it on all the time, just when u turn key. And ya u should have told us about the supercharger service, that more than likely ur issue with that somewhere. Make sure u plugged in all the sensors. Run a smoke test to see if ur gasket is sealing.

 

Sound junky I agree with you & can assure you that they will be covering their screw up! Japeatr your on the right path I was thinking that maybe they did forget to plug back in the BARO sensor after cleaning out the tb. I left them a msg this morning telling them to please check the BARO & MAP sensors. I also read that the seals on those sensors can become damaged & that could cause this as well. I told them that before we go ripping out my entire fuse box I want them to take their multimeter & check every fuse in my box 1st then I want them to check my sensors & mainly the ones in the problem area which would be the BARO & map sensors. I'm still waiting to here back from them today. Again my tech Jason has taken dam good care of me over the years & he is the shop owner as well however he had to hire some help & his help is who did the boost gauge install & is also the one who is working on my car right now. My tech Jason is out racing this weekend however I know when he gets back in the shop on Monday if his help hasn't fixed the problem that he will so I want to give Jason a chance to look at it here. Like I said in the past when I've had the reduced engine power issue the dealer has always replaced my MAP sensor & that has always fixed the problem which is why I'm asking for them to check that as well as the BARO sensor.

Do you guys think that with the added air flow now that my snout bearings have been replaced that could be what's messing with the pressure corilastion ?

 

Thanks Tom my tech Jason did the sc rebuild & I stood right there and watched him do it however you could be right about the sc gasket having a leak. I did not replace the sc gasket this time around because it is only about 6mths old. I will have them check it though.

I would like to say that my stage 2 belt has never squeaked & now when I start my car it squeals for about a minute & then goes away but I don't think that would have anything to do with this.

 

Ok guys so I just got off the phone with the shop they agree with us now they don't think this was caused by the boost gauge install or the fuse box needing replaced they said that the car runs fine & idles fine they said it will sit there all day & idle however the 2nd they get it out on the rd & put some torque & shift gears on that engine is when we through the reduced engine power the cel light & all of the codes they also said something about a 5v reference as well so they think that when they put my supercharger back on that they may have punched one of the wires in there somewhere. Does this sound right to you guys could this all be from a pinched wire ? Anyhow there going to take the sc back off & check all of the wiring & see if we don't have a pinched or torn wire in there from when we had the sc off & then put it back on

 

Yea i would definitely seek reimbursement for the tow since it seems like they f'd something up during the sc rebuild.

 

So just a follow up on my cobalt issue guys my tech has had my car for almost a full week now he's had it on the rack & off the rack & back on again he just can't seem to find what's wrong. He said that he thought he had it fixed he found a bad wire or harness over by the throttle body so he replaced that took it for a spin everything seemed fine & then a couple hours later he took it out again & he got the same dam reduced engine power cel & same four codes thrown. He said something about a 5 volt reference code which is making him think that it's a wiring issue that was caused by that dam boost gauge install. He said he's tracing back all of the wires trying to find the bad wire that could be causing all of this. He said if he has to he will remove the entire wiring harness in order to find the issue. I asked him if he thinks this could have been caused by the SC rebuild & he said no the only thing we did was out bearings in it & he said the seal is good so it has to be from the boost gauge install.

He did check all of my vacuum lines & didn't find a single leak so that's not the issue. I did tell him from past experience about 3 times now since I've owned this car I've experienced this reduced engine power crap & all 3 times I would take it to the dealer where I bought it from they would always say that it's my inlet MAP sensor they would replace it & I would be good to go so I went ahead & picked up a new inlet MAP sensor from ZZP along with a vacuum hose kit.

I'm going to have him install both the MAP sensor as well as the vacuum hose kit to see if that doesn't fix the problem here however anymore advice that you guys could give would be greatly appreciated thanks.