[Isbjorn]

Hey guys, so I have on '06 with the 2.7L engine. I lopped off the stock exhaust just behind the 2-to-1 "y" pipe and welded in 3 inch the rest of the way back. My car didn't immediately show the code but eventually it did, P0420. I thought, "ok, no big deal. Just swap out O2 sensors and be done with it." That worked for about a month and the code came back. No big deal, car seems to run fine and I have a few months to work the problem out before emissions rolls around. So, I ordered new cats (the company said they were eom quality) same pipe size as my factory cats... It didn't fix the code. I took it to a shop and paid their $350 diag fee so I can figure it out. They said my new O2 sensors were low quality and that should fix the problem. Ok, I bought higher quality sensors and installed those. That worked long enough for my car to pass emissions and LITERALLY when I started my car after emissions passed and I'm getting ready to leave... CEL turns on. I'm at a loss here. What could it be?

 

[gstr6800]

the car must only use oem o2 sensors. do not use any of the other versions you find out there. i chased my tail for months after i installed an exhaust and headers and sought ways to kill this code. Even extenders will work for limited amount of time.

 

[Wolfie-07Mag]

I changed my CATs to high flow. had codes popping left and right. ended up using those silly little spark plug type extenders to get the tips of the O2 censors out of the direct flow. no codes since. these are not the exact one I have, found these on ebay, only ones. 2 pc Oxygen Sensor Mounting Only Bung M18 x 1.5 | eBay, and after looking around I found these.. FORTLUFT O2 Sensor Spacer - FORTLUFT Auto Parts or FORTLUFT Oxygen Sensor Extender - FORTLUFT Auto Parts

 

[gstr6800]

Yeah, I used the same but threw codes after a few weeks of driving. I eventually went to green cats. Then again, I have a blown V8, so they do not have the same solutions as the V6s.

 

[Wolfie-07Mag]

Yeah, I used the same but threw codes after a few weeks of driving. I eventually went to green cats. Then again, I have a blown V8, so they do not have the same solutions as the V6s.

and then again. a tuner can just turn those pesky little censors off lol