Had two CEL codes last night p0171 and p1174. Ask a few questions for some things to try. Got up this morning also had a p0300 and my truck wouldnt run. It would start but not run. Cleaned the MAF sensor, TB, air filter, and changed the spark plugs, all were so dirty not sure which one fixed it but all codes are gone. Spark plugs where very bad at only 60k miles. Also changed the oil today and de-blinged her the rest of the way.

Would add some photos, but not sure how. Keeps asking for a web address?

 

The old spring cleaning....glad it has worked.

P1174 could have been a vacuum leak, but it can also be from an O2 sensor not responding properly. P0300 can also be O2 sensor related, but might be telling you a coil pack is not firing correctly (check the wiring to each pack). Since it isP0300 (the last digit is supposed to tell you which cylinder the imbalance or misfire is coming from) it means it could be a random problem or the PCM just can't tell. So, if the CEL comes back, check the coil packs and then think O2 sensor.


To post pics, set up a photo storage account (they are free), like with Photobucket or Flicker etc.... Put whatever pics you want to post in your photo storage and then you copy the image link to your post. Otherwise you can post thumbnails from your computer but they have a tight size limit.

 

This is why I always recommend what you did to folks who are experiencing "rough idle!" Mine was the same way (without the codes) and cleaning all those items w/spark plug changed made my 3 run like brand new. My guess is its this crappy fuel we got. Congrats on the fix!

I just posted a thread related to that Upstream O2 sensor, my guess is that after blasting all that crap out of my engine it messed up the O2. They are really affordable from Rockauto.com.

 

Ok thanks. Doc took your advice again and started a photobucket album.

 

great posts

 

runs kinda rough at dead idle (600RPM) but after that it is fine. O2 sensor maybe or look at vacuum leaks first? Gonna start first thing in the morning.

 

po300 is generally a code for "random multiple misfires" ....301 would be cylinder 1 misfire, 302 cylinder 2, and so forth........if it runs on all cylinders after spark plugs replaced, I'd say it was the plugs......misfire codes can cause o2 sensor codes due to raw fuel flowing into exhaust from misfire......