Hey guys, I installed a catless downpipe that doesn't include a rear O2 bung. So the rear O2 is zip tied to the chassis. The COT is set to all 1's in HP tuners. Problem is you can see on the RPD that the AFR fluctuates from where it should be down to 10.8 anytime the car is running (cruise, idle, and WOT). This causes the car to slightly hesitate and even buck when going that rich. Im assuming its doing this because its thinking the cat is overheating. When I unplug the rear sensor everything is fine, problem is resolved. I'd like to keep the rear O2 plugged in for emissions reasons but don't want to have this problem. What do you think I can do to resolve this?

 

Weld a bung in the DP and run a J spacer

 

Don't waste your time.

I spelled this all out to the guy on Facebook and he won't take the correct answers.

Askhole.

 

This guy haha. I explained why I need a rear o2 plugged in and he tells me just unplug it. Which won't help what so ever. Either he can't read or his comprehension level is low. His response just shows his stupidity. Now people have to read through his counterproductive comments to see what options other people has offered to help before they respond. Smh.

 

You have a catless downpipe and you want to keep the rear o2 sensor plugged in for emisssions? Do you not understand how the ecu works with regard to emissions?

Your options are weld in a bung or unplug it, which both will fail ecu emissions tests.

 

It's because he explained the option that works for your situation from a parts standpoint, you're not going to win the emissions thing with a catless downpipe

 

Listen guys. I told you the reason why I needed the sensor plugged in. I can pass since I have the o2 heater showing ready because the sensor is plugged in. I'm allowed 2 sensors to fail, catalyst and o2 sensor due to catless dp they won't show ready. Everything else will show ready. What you both fail to realize is that I'm asking a simple question in regards to solving the fueling issue with the sensor plugged in. He gave me useless information not pertaining to my problem then when I copied and paste the same sentence I wrote in my original post negating his comment he processes to bash on me instead of offering help. Again showing his stupidity. If you can't help don't respond. Just keep on scrolling. But he felt like being a dick instead. Smdh.

 

Listen, you can't fix the fueling issue any other way. Again with understanding how the ecu controls fueling related to emissions it will continue to dump fuel no matter what changes you make to the overtemp table.

 

Thank you! See there's a difference between you and him. Your giving useful information. I appreciate it.

 

It's not cat overtemp, it's secondary O2 diagnostics. The car adds fuel and looks for a response from the O2. Put it back in the exhaust stream and it will stop. Easy fix.

 

I spelled that all out to you and you felt the zip tie method was better.

 

I hate when people do that...............

Go get your automotive sympathy somewhere else you no-gooder!

 

If ya ask the same questions in enough places eventually someone will give you an answer you approve of albeit the wrong answer.