Hello, I just bought a 98 dodge dakota sport 2.5l manual transmission just about two weeks ago now from a coworker.

He would drive the truck to work at least once a week (sometimes twice). He got a CEL code for a bad cat. Cat was replaced and he drove it twice to and from work (about 25 miles each way) before I bought it.

I drove it home and it was fine. 4 days later I drove it for a turn around errand about 30 miles each way. On the way back whenever I would get to a red light or stop sign it would sputter and want to turn off. I would have to press slightly on the gas so it wouldn't die but the CEL never came on. 3 days after that I took it for a 30 mile drive (started up and drove great most of the time) Just about 2 exits away from my off ramp it started to lose power. When I got to the red light it was wanting to turn off once again. I managed to get it to my destination but this time the CEL started to blink and stayed on permanently.

The engine sputters and sounds like a misfire. You can also smell gas. I put a scanner to it and it gave me a cylinder 1 misfire code. Replaced all plugs (autolite iridium), wires (denso) cap and rotor. Went to start it and its still sounds and acts the same.
Did a cylinder pressure test and checked the fuel injectors. It seems like the injectors are staying open or are opening too much causing too much fuel to the cylinders.

My guess is a bad pcm but not sure.


Any help would be appreciated.

 

DakAZ is the resident 2.5 expert. But usually a rich condition will plug the cat, so everything sounds about right.

What are oxygen sensors showing on the scanner? I would start with those.

 

Get rid of the iridium plugs too. These trucks just don't like the rare-earth fellers. Standard copper plugs only please.

The blinking check engine lite is telling you it's misfiring. (hence, the code) You only got a code for #1 though..... so, can't be anything really bad. (the 4 bangers are notoriously indestructible.)

 

Yep as Hey You said change those plugs ! An be sure the 02 sensors are reading correctly an are NOT off brand , same with other sensors like IAC an TPS,- OEM only .
Check injector signal also by switching them an retesting.
Many times fuel trim readings tell if cat is plugged too.
A while back I had a misfire on cyl3 an did a cyl test, an seafoam cleanout in throttle , an tested injector signal an then after cleanout -rerun an reset -- an code went away , but your cat issues an 02 can factor it .

 

Cyl pressure test passed.
Catalytic Converter is brand new.

I'll be taking the injectors out to clean them. Going to order the copper plugs and O2 sensors... good place to start and go from there. (What brand plugs should I go with)

If its the same then I'll do the IAC and TPS probably along with the cam and crank sensors too.

Does Mopar still make these sensors for this year truck?