o2 Sensor suggested troubleshooting

[apache13]

Hey all! It's been a while since I've posted anything...I've been checking in time to time though on some posts. I poured over the O2 Sensor posts but I'm still kind of confused on how I should start my troubleshooting. Within the last week, I've been pulling:

PCM P0135

PCM P0147

PCM P0155

PCM P1441

and these codes are all current (I've reset a few times and they come back right away). I checked the O2 fuses under the hood hoping for a quick fix but they're good. I've read that the next step should be to check the common ground for the O2 sensors (which I'll be doing Thursday on my day off); what do I need to do after this? I'm pretty sure it must be electrical because they all just shot codes together and I'm pretty confident that the ground is fine (I'll verify Thursday). Any help/recommendation is greatly appreciated!

-Tony

[Cadillac Jim]

P0135 Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 1

P0147 Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 3

P0155 Heated Oxygen Sensor (HO2S) Heater Performance Bank 2 Sensor 1

P1441 Evaporative Emission (EVAP) System Flow During Non-Purge

If there is one thing causing all the codes, the EVAP solenoid is stuck open and flowing gas in both directions, so that the fuel injection isn't controlling the mixture. Another possibility is the heating circuit on three of your four oxygen sensors isn't getting power, which would be a fuse, but the EVAP system flow means that a valve is stuck or that a hose is leaking. I would start by checking over the EVAP system for good hoses and connections, and no cracks or leaks, and check the solenoid. Once the EVAP system is fixed I would reset the HO2 sensor codes and see if they come back.

[apache13]

P0135 Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 1

P0147 Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 3

P0155 Heated Oxygen Sensor (HO2S) Heater Performance Bank 2 Sensor 1

P1441 Evaporative Emission (EVAP) System Flow During Non-Purge

If there is one thing causing all the codes, the EVAP solenoid is stuck open and flowing gas in both directions, so that the fuel injection isn't controlling the mixture. Another possibility is the heating circuit on three of your four oxygen sensors isn't getting power, which would be a fuse, but the EVAP system flow means that a valve is stuck or that a hose is leaking. I would start by checking over the EVAP system for good hoses and connections, and no cracks or leaks, and check the solenoid. Once the EVAP system is fixed I would reset the HO2 sensor codes and see if they come back.

Where is the actual EVAP solenoid located? How is it's accessability? Thanks Jims_97_ETC, I really do appreciate it man

-Tony

[Cadillac Jim]

The procedure for changing it is in the 1997 FSM, page 6-769. It's under the intake manifold top cover, which comes off with four screws (torque spec 18 in-lb) to expose the plug wires and fuel injection intake air piping. It's on the driver's side nad has a connector coming in from the right, looking from the radiator. There is only one bolt holding it (torque spec 106 in-lb).

The location description on page 6-275 is "Left hand rear of the engine, on the cam cover, near the ignition coils." It's just a few inches from the EGR valve, toward the engine.