Ok i will test IAC, I will have to go buy a ohm meter though. I have noticed when its just idling it doesn't sound that bad, you can tell it has a slight miss under no load when you rev the motor, when u put it in gear and and hit the gas and hold the brake it wont even think of spinning the tires on my smooth garage floor, That's when it is most noticible. Is it possible that the COP'S and plugs are shot without throwing a missfire code, but throw a p0174 code? I do have about 140k on the original cop's i beleive. Is there a way I can test the COP'S? I did notice when I took the cop's out #6 #7 #8 the spark plug wholes were full of water, I blew those out and let the cop's sit out for a couple hours before putting them back in but didnt seem to change much.

 

Lastly, Again I say, check the IAC sensor out and eliminate it as a cause to some of your problems.

Good luck with it.

 

This added info was a big help, sorry to say, you have some money to spend but your truck will be happy in the end for sure. Plan on replacing that CAT. If I had one that looked like a glow-plug, it would be gone and replaced ASAP.

 

i will check the pvc tube, i am not sure of the modis being able to check cop's, all he said was it didnt show a missfire so that would eliminate injector, spark plug, and cop problems. And yes both of the converters were glowing. But i will check the IAC here soon. have to wait for my boys grandfather to pick him up before i head to the store to get a ohm meter. Thanks for the help and Ill report back in a bit. Is there a way to test the COP'S witht the ohm meter to determin they are good or bad?

 

Ok I jsut read your last post, so you are saying that if the cop's are bad they can also throw the p0174 code instead of a missfire code? I dont mind the money aspect of it, but I refuse to take it to a place around here to do it when i am capable of following directions. And I am pretty mechanically inclined, well an excellent parts changer is a better word for it. LOL

 

Make sure know one shoved something up your tailpipe lol - not kidding. Then get those cats off there pronto. Install new ones

 

Do you have the tools to remove the CATS and replace them in your garage. This CAT problem is going to cause you more problems and probably make your repairs difficult by giving you bogus info and running conditions. If they both glowed RED, they are toast I believe. Jbrew knows a kid on this site who is an exhaust expert. Maybe he can chime in and help with this matter.

 

No there is nothing in the tail pipe, I was driving home from work at about 1am and the road was pretty much drifted shut, When I got home it was running great, when I came out the next morning and started it it is when the problem started. So i popped the hood and there was snow on top of the cops 6,7,8 and the air filter had snow around it. So i am still leaning Cop's are bad, but it messes with my head because there is no missfire code.

 

Well the cats are an issue for sure, any good suggestion or what to put in its place, ( cost affective not dealership prices). And from past experiences the nuts on the manifolds are a pain to get off right? There is a good exhaust shop 2 blocks from me.

 

The one thing I refuse to work on is the exhaust system unless it is a coat hanger emergency job. Well I do my own O2 Sensor work also.
Thankfully I have Teddy for my exhaust work. We actually own the same identical trucks. He's pee'd tho because his body was in better shape and then I had my truck completely done, body wise. Sorry for the rambling, bored waiting for my son to wake up.

 

Sounds like there's more going on here really. - Cats are red because their on fire and burning up. You could even be in "Limp Mode" PCM isn't giving your injectors what they need. Caused from terrible maintenance. One problem lead to another and another like domino's. You need to go thru it now. Some of the fuel you are getting isn't combusting because there's nothing to light it lol. Raw and unburned, therefor, your O2's are fouled and cats are fuel soaked. IAT's don't really go bad to often, unless you break a wire. MAF is probably dirty as hell - Just one of the problems.

I have know idea why you not getting more codes ???? You should be.

I could be wrong to some extent - Hard to say without knowing the history and order of events. Idunno, something funny here

AIR INLET TEMPERATURE (AIT)

P0112 Intake Air Temperature Circuit Low Input

P0113 Intake Air Temperature Circuit High Input

The IAT sensor is a temperature sensitive resistor (thermistor) connected to the internal resistor network in the Powertrain Control Module, the EECV, and it provides a output voltage inversely proportional to the intake air temperature. The PCM uses this input as a corrector for airflow calculations, to proportion the cold enrichment fuel flow and to modify spark advance.

Typical Malfunction Thresholds: Voltage <0.20V or Voltage >4.80 V

 

I doubt it.

 

Well what should the multimeter be set on to test the coils, i put it 2000k ohms and it shoots up then comes back down to the number 5 and 6 and fluctuates. How does limp mode work. is there a way i can reset it?

 

Why reset it? - You have to fix the problems first. She goes into Limp mode to protect your cats. I don't think it helped if that's the case.

I think you should take it in.

 

What meter did you buy. If you can't post a pic, find the website of the name-brand you bought and post the web-site in 1 of your posts.
Like Brew said, you have to fix a few things 1st that are obvious repairs. Then you can do an erase on your DTC's including the pending DTC's with your friends Modis unit. Basically clears the PCM and resets the PCM to original factory parameter's so it has to re-learn the driving parameter's.
I think that came across right, if not Jbrew and a few others will give me a thrashing if it didn't.