Hi everyone,


I have a 2000 Monte with the L36.
Been having this issue for awhile. It's pretty much the description about having a bad cat or something similar. At around 80km (50mph) when I'm at maybe 2500-3000rpms the car would hesitate when accelerating gradually but if I give it more gas there wouldn't be that issue and once in a higher speed everything is fine. I used to have the check engine light for the sensor in the back which would sometimes indicate a bad cat.
I ended up getting a down pipe and deleted the cat and got a cat back exhaust system with an ecu tune from ZZP. After doing that the car ran perfectly fine but then a month or so after driving the car the same issue came back. I don't have any codes or check engine light.
What could be causing it?

Thanks

 

I would guess carbon build up inside the throttle body. Check for codes again maybe something is hidden. Might also need a tune up depending when you did it the last time. Check the air filter, make sure its not dirty or clogged up. When you say you deleted the cat does it mean you removed? have you removed any components related to the exhaust system, u-bend delete? I hope that helps. I'd wait for an expert to give you a more thorough diagnosis.

Peace

 

Clean your MAF

 

clean your intake but it sounds like your ECU because it was fine just after you got it, i would try to check the codes again

 

Thanks all. Ya I don't have a cat anymore. When I got the downpipe I didn't get the cat with it. Pretty much it's downpipe straight to cat-back.
I'm going to give the throttle body a clean since I notice that the gas pedal is a bit stuck in the morning when I press on it.
If anyone else can give me ideas it'd be much appreciated, thanks

 

had the exact same problem. Dealership ended up overhauling my transmission. W/ my car, it had a bad valve body in the transmission