Hello all, I keep getting a p0152 after going to the car wash. Particularly after rinsing front wheel wells.

I thought originally that the spark plug wires were shot, but I have done a complete ac delco tune up and it still happens. I also feel a light rough / idle issue when I’m in park still. The plugs , wires, coil, icm are all replaced.


After the wash, the car runs really rough and pops for a minute or two. What should I check? I thought the 0152 was from a misfire, but I have no other codes. I’m completely stumped.

 

P0152 means that the Bank 2 Sensor 1 (pass side, pre cat) Oxygen sensor circuit is seeing anout of bounds voltage condition, in particular the voltage is too high for too long. This can be due to many things:

1. The O2 sensor is bad
2. The wiring in that circuit is bad
3. There is a short to power on the signal wire
4. The ECM is bad
5. The computer has lost fuel control from bad injectors, wiring, power, ground, etc

The fact that this happen when the truck gets wet suggests that its wiring related either in the O2 sensor circuit or the fuel control circuit. I would start by confirming the condition by watching the O2 sensor graph in live data when you create the failure at the car wash. The sensor should be switching between around 0.15V and 0.85v at around one cycle per second at idle and then peg high and stop switching for at least 10 seconds when it fails and generates the code. If the condition is verified then the hunt begins to locate the problem. I would start by inspecting the O2 sensor wiring and fuel control wiring. Then unplug the sensor and see if the voltage goes to 0.45v in live data (during a failure). Then an inexpensive shade tree mechanic trynostic move would be to switch pre cat sensors and see if the problem follows or stays with the passenger side. That will get you started. Report back and we can go from there.

George

 

Thanks George, wiring is probably the culprit, the plug seems to be right on the frame rail there near the wheel well. I just tugged on it slightly and inside the loom was full of water.


I think all of the sensors are original to the tune of 132k on my 2000 LS, afraid to pull one and switch it, will they come out easy?

im in Buffalo, salt and rust and harsh.

 

Even with a tune up, the idle seems a tad rough, cleaned IAC, checked EGR, nothing seems unordinary. Wondering if that sensor has been going bad. Drives fine beyond idle, no missing!

 

I am betting on wiring or connector. Yes the sensor can be tough coming out. You will need an O2 sensor wrench, possibly some PB Blaster and if really bad, some heat. There are a couple of wrench styles but here is one option:



That said, you can start with the other steps and leave the sensors alone for now.


George