I didn't see you mention the coil.

Have a 2000 blazer v6 mileage went to s**t.
Didn't check the codes but the check engine light was blinking as I would drive it. Wouldn't pull a greased string out of a cat's a$*. Was dangerous to pull out on the road.

Popped the hood one night and the thing was lighting up like a Christmas tree.
Had to replace coil, plug wires, rotor button and cap. Disconnected battery to clear trouble codes and so the engine/computer could learn the new parts. No trouble since that was 9 months ago.

 

I did not do the coil just for $$ reasons at the time of the tune up. I am going back to do that next. .

When I checked the pcm plugs the other day. ... it cleared the codes. . I got a little excited there for a minute when I saw the light off but then I realized what happened. . Anyway. ... The light came back on but now its only reading two codes (for now anyway) p0174 and p0442. .
Would that indicate the 0174 is the primary fault and all others stem off of it?

 

At night pop the hood. disconnect the light under the hood. look for arks and sparks. The darker the better.

 

Yeah.. tried that.. wasn't able to see any arcing...

 

OK, so I am still battling this. The fuel pressure is fine and we checked the first and third injector with a test meter. They both ohmed the same. (so I don't think it is a bad injector).

 

Just rereading through the thread.

In post #10 about the "mass flow" if you mean MAF, we don't have them. It use a MAP sensor instead.

Your question in post #12 about the P0174 codes and others following, it does not mean P0174 is the "primary" fault. They just get displayed in numeric order.

Ohming out the injector won't tell you if it's bad always. It may be fine electrically but the nozzle could be clogged or have a very poor spray pattern.

Are you showing the same codes? If it's the P0174 have you changed the O2 sensor? Don't use Bosch.

 

I still have the same codes but now have added the rest of the cylinders to the 020# list. And they are not in numerical order. That is why I thought that signified the the order.
I have held off getting the O2 sensor for 2 reasons. 1st I just didn't think it would cause a electronic malfunction and 2nd from my understanding 9 out of 10 times a bad 02 sensor code is a result of another problem not the cause of one. (Not saying it wouldn't go bad. .. but usually it is something else)

Is there a way to test the computer? There should be a constant hot wire on the injector. Correct? If that is the case, could I turn the key on and check voltage?

 

I find your reason for not

Quote:

getting the O2 sensor

bizarre and founded on nothing.

To me a bad PCM sounds like a good possibility

I would follow what 00DakDan suggests I would also say I have never seen the injectors as being the problem in most cases bad spray yes but outright bad no.

 

Only with the engine running is there a constant hot to the injectors. The ground is switched to trigger them. If the engine isn't running the ASD relay will cut power.

There is no real way to test the PCM. It does "self test" and can check for a bad checksum which will display a code. A DRB (dealer) can look at more of it but it's probably cheaper to get a rebuilt unit online and swap it yourself.

At this point I'd be swapping the PCM and the O2 sensor. Not necessarily in that order.

You did swap the coil, right?

 

It is founded. It is founded on experience, multiple conversations with dealers, mechanics and other people who had O2 sensor issues.
Regardless. ...
Thank you for the responses. I fear it's time to start looking for the PCM.