My friend has a small cutout after his headers. Its about 8-10" from the O2 sensor.

Will this cause an error code saying that side is lean? Or is it that the O2 has gone bad?

 

at idle maybe, under load- nah. But then again you dont use your O2 sensors at WOT anyway so ehh, its a possibility.

 

well id say no but easy way to check is to switch the sensors from side to side and see if the error follows the sensor.

 

Does the problem exist when the cutout is open or closed or both? If your side isn't lean when the cutout is closed, then I would say it is causing your problem.

 

I just got an electric QTEC cutout for the car and after reading this post I'm wondering where exactly to put the cutout so that way I will have less of a chance of running into this type of problem. Where is the best place to put the cutout?? I should mention that I have MAC headers and their off-road y-pipe on my car. Will this problem occur regardless of position of the cutout? Thanks.

 

well he capped off the cutout and it still throws the code after about 20 mins of driving.

Could he be burning an O2 sensor wire?

any other suggestions?

 

Check the O2 sensors. Have you checked the code to make sure which one it is? It should tell what's going on if so.

 

The injectors are new and have about 5K miles on them. Car feels like it has all the power but the ses light gives two error codes for that side.

Error 55: Lean Fuel monitor

Error 64: Right Oxygen sensor lean

 

clear the codes

un cap the cut out and drive it on the freeway, street, everywhere

if the light doesnt come back, then your cut out is the problem. A leak in the exhaust system sucks air, and if that air passes by the 02 sensor, it will go lean in a heartbeat. a loose 02 sensor sucks air too and creates lean codes. I've seen it happen.

 

Car throws codes with cutout capped and uncapped.

Will a burnt O2 wire also cause these errors?

 

yeah, ALL wires must be intact

if the signal wire is melted against the exhaust, it will ground, thus pulling the 02 voltage down to 0.02 = leaner than crap

do you know what the voltage reads on that sensor?

 

No I don't.

Thanx for your help.

I'll check it out when he comes by today.