i have a 96 3.9 that recently started acting up. It starts up and idles fine but when driving, it will go good for the first few mins but then just drops power. If i goose it a Little i can get it out of it for a few mins but its right back to the same thing after. if i hold the pedal down it acts like its running out of fuel and coughs but put it to the floor it takes right off. going to run codes and be back soon. any help is appreciated.

 

I have the same 4 codes ive had for months 3 are from the o2, engine lean, engine rich and o2 circuit high.. the previous owners put a ghetto exhaust on it and didnt put the cat on. also didnt put a hole for the downstream o2 in( after cat?) and then the upstream went out bad on me so i didnt plug it back in, but havent had a problem for months till now.. the other code was voltage low on bank 1 i think..ive just a did a tune up and that did nothing

 

o2 sensor went a LONG way to fix my power problems when I put it in. I suggest replacing it. Tough as heck to get it out.

 

Just use a breaker bar with a pipe on the end of it. comes right out.

 

I know thats why i havent changed it yet lol... wouldnt the o2 sensor cause the problem rigth away? its been unplugged for months.. also the downstream just monitors the cat, right? so i dont need it if the engine light dont bother me

 

use the breaker bar and replace it. it will make a difference. $40 well spent.