[Pxquette]

New to the forum but I have been reading through relatable issues and don't think I've landed on one I can say is my exact situation.

I bought my car straight piped with the OEM downpipe, ofcourse got used to the noise and moved onto a catless downpipe (now full 3" piping) I immediately got multiple codes, long story short I cleared most by changing my spark plugs but I still have cylinder 1 & 3 misfire codes. I don't have my sensors in yet as I want to use an o2 spacer or something similar.

I also have a 3" resonator ready to be attached to help with the back pressure but not sure if I need it since the car may be in limp mode due to the missing o2 sensors??

Any thoughts or suggestions are welcome, my backup plan is to put the cat back on but I'd rather try the last 2 ways out first.

 

[Moreno.t]

New to the forum but I have been reading through relatable issues and don't think I've landed on one I can say is my exact situation.

I bought my car straight piped with the OEM downpipe, ofcourse got used to the noise and moved onto a catless downpipe (now full 3" piping) I immediately got multiple codes, long story short I cleared most by changing my spark plugs but I still have cylinder 1 & 3 misfire codes. I don't have my sensors in yet as I want to use an o2 spacer or something similar.

I also have a 3" resonator ready to be attached to help with the back pressure but not sure if I need it since the car may be in limp mode due to the missing o2 sensors??

Any thoughts or suggestions are welcome, my backup plan is to put the cat back on but I'd rather try the last 2 ways out first.

Making sure, Is it a turbo?
If so... low Back pressure after the exhaust turbine should not affect your engine unless you have a blockage in your cat or in your exhaust pipe.
I have a Magnaflow Catback Exhaust with a High Flow Cat and Resonator and did not have that issue when installing my downpipe. You might want to get those O2 sensors in first.

 

[trdtoy]

You need the sensors in the exhaust for sure along with proper parts and tune to run well without issue.

 

[Pxquette]

as a follow up, I put the o2 sensors in with spacers, still having a rough idle and feeling like a misfire or definite loss of power once I'm 60-70% on the throttle, no CEL's at the moment & haven't put the resonator on yet thanks for the input guys

 

[trdtoy]

Spacers are not needed.

You need good maintenance, proper parts, proper tune, and good fuel for the car to run well no issues. One or more of these are off if you have issues.