I'm having a problem with a 03 Dodge Caravan spitting out
P0302 & P0172 codes. So far we did a complete tune up and swapped out the pcv valve. Still running like sh!t... Any recommendations?

Dave,

Do you have the definition of the codes? If not, here they are:

P0301 to P0312 — Cylinder misfire detected where the last two digits are the cylinder number, e.g. P0303 = cylinder #3.

•P0172 Fuel Trim System Rich Bank 1

It almost seems as if there is potentially an issue with an injector hanging open a bit much and fouling a plug, or something with the fuel pressure regulating system.

-Justin

Have you done a compression check on on the engine, especially cylinder #2? What ever is causing your misfire is likely causing the rich DTC. If compression is good and even with the others, id say you might have an injector issue as mentioned above.

Thanks! I'll do a compression test and go from there..

A complete tune up as in plugs and wires? Check and make sure you have good spark out of the #2 coil.

Had the same issues with my 05. The codes even sound familiar, although it's been some time. I did the plugs, wires, coil, and even the injector on the bad cylinder with no success. A great mechanic that just wouldn't give up found that the wiring harness that goes from the top front to the rear of the engine on the drivers side of the engine had worn through and was shorting out. It was rubbing on the sharp corner of the head where it bent around. Maybe? Ya never know...just might be a similar issue.

You could have a bad injector. Move the #2 injector to a different position. See if your misfire changes. If so, replace the injector.