Still down on power after loose downpipe tightened

[3pedaldevil]

Hi all,

First post here. I have a 2015 FiST, COBB stage 3 (Stage 3/93 tune running on Chevron 94). Mods were done at a friend's shop back in April and the car was great up until about a week ago when I started smelling fumes in the cabin. It turned out one of the bolts on the downpipe had fallen out and the other ones were loose. They tightened it up for me and the car feels a lot better, but I can still hear what sounds like a leak somewhere when I get into the boost. It's a similar sound to when the downpipe was loose, but that should be tight now. I'm definitely missing torque everywhere--used to be able to blow the front tires off in 3rd, even 4th with ESC off but I can barely get them to break in 2nd now (yes, I'm a complete hooligan).

So my question is, is it normal for things to loosen off over time, or was the original install done badly? Obviously there's still something wrong and I'm trying to decide whether to trust these guys for another look. I wish I had the space/time to get under it myself and learn a few things but unfortunately I don't right now.

Thanks for any thoughts/advice.

 

[me32]

Was a gasket used?

 

[yackyz]

If I was you I would check Fuel pressure, boost, AFR. Maybe get a boost leak somewhere, as previously stated a gasket or a clamp maybe. How many miles are on the vehicle?

 

[3pedaldevil]

Thanks for the replies. I'm not sure if a gasket was used--I know there was one in the kit but I'll check if it's on there. I'll collect some numbers with the access port and report back.

Thanks again.

 

[3pedaldevil]

Also, 5,600 miles on the car.

 

[3pedaldevil]

Just to follow up, things have gone from bad to worse, there's definitely a massive leak and I think it's somewhere in the exhaust back of the downpipe. Found a COBB gasket (still in the package) in my spare parts

 

[jeff]

Just to follow up, things have gone from bad to worse, there's definitely a massive leak and I think it's somewhere in the exhaust back of the downpipe. Found a COBB gasket (still in the package) in my spare parts

Then good news is that the Cobb gasket is very easy to install. All you have to do is get under the car, remove the two bolts that mate the downpipe to the exhaust, insert gasket, and tighten. Should take 10 minutes and no cussing. Good luck, that may fix your problem.

On another note, I would never trust my brand-new car to a mechanic I was unsure of, you better be careful in the future, that was pretty unwise.

 

[me32]

Keep us updated. Sounds like the shop you used isnt in the known for these cars.

 

[3pedaldevil]

Alright gasket installed and found another problem at the same time: one of the brackets on the cobb intercooler pipe had snapped off leaving a small hole. I've wrapped that in piece of heftly aluminum tape and 4 clamps until I can get it welded. I've asked cobb, but I have to assume it was an install error that put that much stress on the bracket.

Lesson learned about trusting a shop without a reputation for these cars. Good news is that everything is 110% now so I can get back to terrorizing vancouver

Thanks guys.

 

[yackyz]

Alright gasket installed and found another problem at the same time: one of the brackets on the cobb intercooler pipe had snapped off leaving a small hole. I've wrapped that in piece of heftly aluminum tape and 4 clamps until I can get it welded. I've asked cobb, but I have to assume it was an install error that put that much stress on the bracket.

Lesson learned about trusting a shop without a reputation for these cars. Good news is that everything is 110% now so I can get back to terrorizing vancouver

Thanks guys.

To my understanding this is a common problem with the COBB intercooler piping. As far as the exhaust gasket that's inexcusable. Oh and lesson learned "Dont take it to a shop"

 

[me32]

Let us know how it runs