Z28Camaro30Ann

iTrader: (15)

Ok. I got an SES light on. Read computer over a week ago and came up with a P0336 (Crankshaft Position Sensor) The computer said "PCM has determined that the voltage signal from CPS "A" is out of range for the current engine operation conditions." SO i rode for a week and checked it again yesterday....came out with a P0336 AND NOW a P0420 (Catalyst Efficiency Low-Bank 1). Ok, so I thought CPS is out, change it and all is well...WRONG! I changed the CPS today...light didnt go out, so I thought well maybe it cleared the 336 but not the 420.....WRONG! Both were still there. And yes, I did disconnect the battery after I finished to reset the SES. No good. What is it? Anyone know???

The Engineer

Sometimes it is best to clear the codes individually with the scanner tool erase function, rather than the battery. Then re-check for pending codes. Additionally, it could be a problem with the CPS wiring harness and not the sensor.

WD

-PEPE-

iTrader: (10)

the Catalyst Effieciency Low-Bank 1 is your driver or pass side pre-CAT 02 Sensor I'm almost positive. If they have not been changed in the last 20k miles depending on the type of fuel you run and emmisions quality your engine is putting out then that is what you need to do, change them both out though. Every time my SES light would come on that was the code it through and changing the 02's made it run like a champ again.

Z28Camaro30Ann

iTrader: (15)

right on, I'll change out those sensors asap. As for the wiring harness, as far as I could follow it, it was good to go. I lost it into black wire loom after a minute of tracing...I gave each wire a small tug or 2 and nothing gave so it "SEEMED" to be connected right.........I dunno. The CPS is there to detect a misfire, and I do not actually HAVE a misfire, but maybe I can fix it this way...I'm gonna change the spark plugs, spark plug wires, and distributor cap/rotor. The wires look like they came with the car, not too pretty if you ask me, and I dont know when the last time the plugs, cap, and rotor were changed...so maybe...JUST MAYBE....that will clear it. Maybe its getting spark and not missing, but not getting "enough" spark so it throws the SES light at me. this is WAY too many maybe's for me to be comfortable.

SLawson86

iTrader: (8)

well it is possible to have wiring faults to the ckp. i actually see it quite a bit. but as far as catalyst efficiency, sorry to burst your bubble, but that usually means the cats or cat are shitting out.