okay, i have a 2007 HR Z. some background info. i hit something in the road about 4 months ago and it broke my 02 sensor on the driver side cat and i welded it back in cuz im going FI. Been working fine ever since, no codes at all. so this code came on, and took it to nissan. they said p2a03. BUT they say since i have a welded 02, that they wont give me a new a/f ratio sensor becuase the welded 02 is making that 02 sensor ON THE EXHAUST MANIFOLD act up. i think this is total BS. ( keep in mind cat and sensor are on same side ) they telling me a need a new cat and new 02 b4 they warranty a new sensor for the exhaust manifold. SO... idk what to do.. can this really cause a problem? I got some exhaust leak fix from autozone and put it all around the 02 on the cat to fix any leak i may have had. also switch the 2 plugs from the cats, so the BAD cat is being read to the other side, so IF the cat is BAD, it now should set off sensor 2 bank 2. I cleared code and now waiting to see if it does pop back up... will update. keep in mind, i have cleared 3 times, and it takes anywhere from 20 to 30 to even 70 miles to make the code come up.. hmm..

 

How is the car running?

 

running fine i think... i dont see any problems. i only drive hwy and im gettin around 21mpg... idk.

 

main reason i wanna fix this asap is cuz im planning on boosting car in 3 weeks... but i wanna make sure everything is safe and good b4 boosting... especially with boost, wanna make sure engine is good on a/f

 

Well if you BOOSting soon then dont worry about it honestly. unless your in cali. lol. What also could of happened the secondary 02 sensor could of went out because i use to get the stupid cell light after 50 miles(test pipes) until i got my tune. Just check every week at you local car parts store and use the scanner to make sure it the 02 code and not anything else. Once you go fi you will not have any warrenty and thats when you really will have to pay.( this is going off of what i know and i could be wrong just my 2cents)

 

well i want the car knowing how much gas/air its pushnig into the motor. isnt that dangorus with FI ?

 

so, like i said earlier, i went under the car, and switched the connectors to the o2 sensors from the cats, so that the cats are now read oposite sides, so i can see if the cat infact is bad. After doin this i get the SES again after about 50 miles, and scanned. NOW im getting code p2a00 sensor 1 b1. SOOO that means the cat that was connected to drivers side, is now reading on passenger side, now thru a code for the passenger side air fuel ratio 02 sensor. so im guessing it really is the cat like nissan said? or is it thorwing this code becuase its reading the wrong side? also keep in mind, the code that was once for the a/f ratio 02 sensor bank2 ( driver side ) there is now no code... hmmm

 

Don't worry about it. Those lights are an annoyance.

 

well david, when i go FI, are the primary o2 sensors of importance? wont the car not know how much fuel/air is mixing? very worried