I have a 3.9L v6 and it took 15.44 seconds from 0-60 Well, Im not sure what the problem is, I put new plugs in, New o2, Removed the cat converter. It idles a tad rough just jumps about 50 rpms at most. (I think this is normal) Im not sure if the o2 is gone agian or what. I has like no power. I have a shift kit in the transmission, So it should be a faster acceleration.

 

It sounds like your TPS might be bad but 50 rpms is hard to notice. As far as idling rough what kind of plugs and wires did you install???

 

ya.. what type of plugs? Also 50rpm idle range is normal, do you have any typw od exhuast leak, this can dog you down alot.. and fry o2 sensors.

 

I put in NGK ones that were made for this truck stock wires, umm nothing else, There is a few exhaust leaks but my o2 might have been burnt out by the backflow of the clogged cat, but it still looks like new.

 

where are the exhuast leaks at? amnd a bad cat is also not good.... if you have exhuast leaks, bad cats and o2's io can see why its running bad.. i say save up and do a full tune up, and fix your exhuast system all together, new cat, muffler, pipes, and headers if you can afford them.

but fix those leaks...

 

No longer is a cat, I cut it out thats fixed my millage alot, there is about 3 leaks, Because of just clamps, They need to be welded in. I might try putting in the old o2 sensor. But the exhaust should be free flow but the new o2 was put in BEFORE I removed it.