Got some codes today as follows

1) P0141 = H02S ? heatercircuit bank 1 sensor 2

2) P0440 = evaporative emission control system

3) P1122 = throttle position sensor circuit. I think this means a current prob.

I have no idea what I need to do to fix these codes. I can turn the engine light off easy enough, but thats just a temp fix. Any ideas what actually needs fixin?

 

Well, seeing as how my internet connection was non-existent last night... Here's my reply I typed up then:

P0440 typically is a loose or faulty gas cap. Just check the o-ring seal on the gas cap and see if there is anything that is stopping a seal. Always tighten the cap until it clicks atleast 3 times. If the code persists, first thing would be to buy a new gas cap. Mine has done this the last 3 times I filled up, but I took some WD40 to the cap and cleaned it up using my air hose to get any excess spray off and I haven't seen it come back. I haven't driven it much since, but I have filled up atleast once.

With the TPS, you can either probe the signal wire to the PCM or check the resistance of the sensor both as the throttle is run from closed to full throttle. If you probe the signal wire, you will be looking at somewhere around 0.5v closed and 4.5-5v open and it should be a steadily increasing voltage. If you are just looking at the resistance, well... I'm not sure where the resistance should be. But it should start out higher and steadily get lower as the throttle is moved from closed to open.

Typically with O2 heater codes, the sensor itself is bad. What year is your truck? Do you have 3 or 4 O2 sensors? If you have 4 (2 upstream, 1 pre-cat, 1 post-cat), then you may want to try swapping the pre & post cat sensors. If you have 3, then you could try switching them, but the B1S2 is a catalyst monitoring sensor only. If you switch it out with one of the upstream (B1S1 or B2S1) sensors, it may effect fuel delivery. Seeing as how this code deals with the B1S2 sensor, I'm assuming that you have a '96-'98 truck... B1S2 would be the sensor immediately in front of the catalytic converter. B1S3 would be directly behind the converter.
Good luck and hope this helps!

 

Thanx Kyle, yeah its a 96 blazer. The gas cap is bad, been that way since we replaced it. Are the 02 sensors the same as the 95's? I have a new one on the shelf.