Throttle Sticking
 

Hey guys, I recently had my CSC swapped and the dealer left off the intake tube off my Stillen gen 3's. I went to pick up my car and it sounded cammed. It threw idle codes and mass air circuit codes. They cleared the codes and put the intake on properly, reset the ecu and the car runs fine. After 100 miles or so i have been noticing that after my car reaches 180 degrees on operating temp, the throttle will lag and start to stick. For example, first gear i shift at 3k it will stay at 3k for a second and then drop. It starts doing this after about 20 minutes of driving. It is very noticeable in first gear only. The maf sensors i have cleaned and it didn't fix the problem. My mods are stillen gen 3s, berk hfcs, and a fast intentions exhaust with 18" resonators. I also threw the codes p2098 and p2096 after they replaced the csc. the codes are popping up every 100 miles. I am untuned. Any ideas on how to fix this throttle sticking issue? The car is a 2014 sport touring with 10k miles on it.

I'm thinking you have an exhaust leak more like. Check your cats for hairline cracks. Should be an easy fix at any muffler shop. Got mine re-welded for $20.

The cats have no scrapes on them at all bro, all bolts are tight. It only does it in first gear mainly too. The cats have 6k miles on them. I will check them anyways though. Any more ideas?


-Raj

You don't need to scrape your cats for them to develop cracks. Heat cycles can easily cause a small leak and that's exactly what your codes are indicating, "bro".

It's an easy check. If it is, it's an easy fix. If it's not, well, you should just hope it's an exhaust leak because electrical gremlins are a nightmare.

If you were so inclined to check instead of getting all defensive about how tight your bolts are, you can use a spray bottle with some soap in it to spray the system down and look for bubbles. If you don't like the idea of a car idling above you, you can also hook up a vacuum cleaner to the tail pipes and seal the off the second exhaust pipe and check for leaks that way. Other tell tail signs are areas with soot present.

Good luck and happy hunting.

PS, do you even track, bro? :p :stirthepot: :rolleyes:

Awesome man, I appreciate the advice, I'll give this a shot tomorrow and see if i can find an exhaust leak! Wasn't intending to be defensive, just stating that bolts are tight. No harm intended

No worries. I'm sure they're very tight bolts. :p

The dealer removed the exhaust for the csc and I'm wondering if he did something wrong like forget the gaskets not tighten them enough. He already damaged a few parts and they are still replacing parts he damaged this week. I'll try this tomorrow, any ideas on replacing the MAF sensor helping?

I really don't think the MAF is the issue. ECUs are quite smart at self diagnosis these days. If it's saying it's a lean trim (too much air) post cat, then it's likely getting the correct voltage from the MAF.

The most likely introduction of air would be either the joint between the headers and the cats, likely a poorly positioned or altogether missing gasket; OR a crack in the weld. When I got those codes it was a crack in the weld. Super easy fix. Hard to detect, though, due to the crack developing on the edge of the weld puddle which was able to hide it from being visible but I could feel and hear the wind coming out of it when the car was idling above me.

Thank you, I'm checking the exhaust system for sure today!


-Raj

The exhaust and high flow cats are good. Any more ideas?


-Raj

The only other thing I can think of is something in the intake. Check one of those innocuous looking black boxes that leads to the vacuum lines and see if those are still in one piece. They have a tendency of cracking open. Not sure what else could be wrong especially since the issue should be post MAF not in front of it.

I have gen 3's bro and I checked and there is no leak :/ I'll keep looking


-Raj

Well it seems to have gone away after running a bottle of Techron through the tank (only halfway through the tank so far) and also cleaning out the throttle bodies. Even though I only have 10k miles on the car it still had throttle bodies that were pretty dirty. Thanks for the advice guys, if anything else pops up I'll be sure to post!


-Raj

Get tuned.

PS. ASAP.

Then my warranty is voided lol


-Raj