- May 13, 2014
- 28
i have just purchased a 05 trailblazor LT with a 4.2 strait six. The other day while driving on the highway at 65 MPH in cruise, the car began speeeding up and slowing down and began acting like it was running out of fuel. iIt would slow down to about 60 and then the trans would down shift trying to get back up to speed.I would then have to floor the pedal and it would bog and then finally speed up. I also notice that the idle at this point would stay at 1000 RPMS. Then it threw a P0171 code. I changed the MAP due to a suggestion on the site with no difference. Then it will go days totally normal. Last night it started up again. this time it wouldn't idle at all and as I was going down the street the revs pulled up to 4000 with my foot off the pedal almost ramming into the back of a car. i had to throw it in neutral and turn off he key. I cleared the codes and today it started again and it just threw 2 codes, P0171 and P0172. Sorry for the rambling post I just can't think of a shorter way to explain it. Any ideas guys. Thanks, Joe