Hi there

im after some help i have a CEL that keeps apearing code P0136 and the odd P0171 now i have checked this against the the code meanings which are a rear 02 sensor malfuction and fuel trim to lean. i had this problem diagnosed at subaru a while back and they said i need a new front a/f sensor for the nice sum of £265 but then i have been advised that this could be from the rear lamda??????? after looking on here i just ended up more confused so is it the front a/f sensor or the rear and were is the location of the front a/f sensor is it in the up pipe pre cat or is it in the headers.

cheers in advance for any help

 

 

The front sensor is in the headers on the righthand side. You can get an o/e denso one for 140 quid so dont get ripped off going to the dealer. The one in the up-pipe is an exhaust gas temp sensor(egt) and can do away with that one along with the rear o2.

 

cheers tez thats good to know cheers for clearing that up mate good news on the £125 saving thanks again.

 

Can the uppipe and rear wires be cut and tied then?
Would a leak in the front of the exhaust somewhere be enough to throw the following errors, I have cleaned the maf with isopropyl since running this though.

P0102 Maf or Vaf A circuit low input.
P0171 Generic, system too lean (bank1)
P0113 IAT sensor 1 Circuit high imput