# Bucking on acceleration



## jblackburn (Apr 14, 2012)

Could just be how they react to knock under load. See if you can monitor knock retard with a scan tool while it happens.


----------



## LBZ123 (8 mo ago)

jblackburn said:


> Could just be how they react to knock under load. See if you can monitor knock retard with a scan tool while it happens.


I have monitored it and it doesn't change, this wasn't a problem the first 130000 miles with the car. I've watched retard, fuel pressure and boost with a scan tool. Nothing stands out.


----------



## RJCruze00 (8 mo ago)

Have you checked your wastegate to see if it’s cracked and wastegate door handle being stuck? Also how many miles does the catalytic converter have?


----------



## LBZ123 (8 mo ago)

RJCruze00 said:


> Have you checked your wastegate to see if it’s cracked and wastegate door handle being stuck? Also how many miles does the catalytic converter have?


No I have not checked that. And the catalytic converter has 165,000 miles on it. I do get a code every 3-4 thousand miles relating to efficiency below threshold bank 2, I don't remember the exact code. The catalytic converter could be causing the problem?


----------



## RJCruze00 (8 mo ago)

LBZ123 said:


> No I have not checked that. And the catalytic converter has 165,000 miles on it. I do get a code every 3-4 thousand miles relating to efficiency below threshold bank 2, I don't remember the exact code. The catalytic converter could be causing the problem?


My catalytic clogged up around 95k, that could be the problem as well as the check engine popping up about that catalytic converter which is a good chance it can be it is clogged. When u apply low throttle the engine is choking up, until u apply more pressure which then gasses can pass through the catalytic, I bought a cat less downpipe from ZZPerformance which fixed my problem, but still check up on the wastegate, a crack is normal on every turbo overtime, but once it’s big enough a lot of boost can escape through it. Plus the door handle not being closed properly all the time from the handle being rusted.


----------



## LBZ123 (8 mo ago)

RJCruze00 said:


> My catalytic clogged up around 95k, that could be the problem as well as the check engine popping up about that catalytic converter which is a good chance it can be it is clogged. When u apply low throttle the engine is choking up, until u apply more pressure which then gasses can pass through the catalytic, I bought a cat less downpipe from ZZPerformance which fixed my problem, but still check up on the wastegate, a crack is normal on every turbo overtime, but once it’s big enough a lot of boost can escape through it. Plus the door handle not being closed properly all the time from the handle being rusted.


Thanks, that's some good insight. Did you get a check engine light from down pipe?


----------



## RJCruze00 (8 mo ago)

LBZ123 said:


> Thanks, that's some good insight. Did you get a check engine light from down pipe?


Yes I did, at first didn’t have any symptoms but after a while my car wasn’t responding well while accelerating


----------

