well as the title says. also it says bank 1 is running lean? im just curious with the front o2 sensor running lean could that cause the rear ones to throw a code? the car has been dyno tuned. please help! thanks in advance

 

Your post is kinda confusing. If you have sims in, you should not be getting any rear o2 codes. Your bank 1 being lean is a whole new story, you might have a bad bank 1 front sensor, or your closed loop tune is off.

 

whats this closed loop tune? and no offense but i posted cuz im not sure why the rear o2's are throwing codes if i have the o2 simms like you said? i will get a new front o2 for sure tho.

anyone else know why might rear o2's are still throwing codes?

 

O2 sims can and do go bad. You shouldn't even need them if the car was dyno tuned. Your tuner should have turned the codes off as part of the deal.

 

well i just bought the o2 simms a few days ago. i was told the tuner deleted the rear o2's but when i got it scanned that was the code being thrown.