2000 Kia sportage 2.0 OBD code 171. System lean, repaired vacuum leak at upper plenum. Dealer installed 2 new injectors prior and didn''t seal upper plenum. no indication of any other vac leaks. Idles little rough without a/c on but runs beautiful otherwise
Kia sportage 2.0Already Tried: Dealer relaced 2 injectors.light came back on. I resealed upper plenum,replaced pcv hose and valve,maf sensor.light came back on.code 171
Hi there!I am assuming you have cleared the code and it has returned?Did you check for vaccum leaks using carb cleaner or propane?
Reply to carguy1's Post: I checked using carb cleaner. cleared code. drove twenty miles,came back on.seems to come on an light throttle cruise.
OK.This code can be a bit tricky.Since you have already done most of the usual suspects,I want to say they need to look at the O2 sensor outputs.The front o2 generally regulates the fuel mixture,however if the rear one thinks it's to rich it will tell the front to lean out the mixture.Sometimes this makes it look like the front O2 is bad but 90% of the time it's the rear reading wrong.Hope this helps!
25years experience,certified subaru technician,Nissan factory trained
I have a snap on scanner. the front 02 output is within range. did not know the rear could affect it like that. do you know what the rear output should be? thank you.
Hang on.I will see if I can get the info for you.
OK.Here is some info for slow responce on the rear O2 sensor.The max voltage you should see from the sensor is 1.0 volt.That is all it is capable of making for voltage.If it stays lower,toward like.3 volts then it will tell the ecm to lean out the mixture.Now,when I was looking up the P0171 code it also said to check the purge control valve.If it is stuck open it will cause a small vaccum leak that you will not find with the carb cleaner.Just a thought,since you have a scanner,you can moniter the pressure sensor and make sure the voltage is changing while the warm fuel from the return line is going back in the tank.