I have a 99 Ranger XLT 3.0 that the engine has been replaced as it was running bad and the mechanic I took it to said there was no compression on the #3 cylinder. He replaced the engine with an engine that has 143K on it. It has never run that great but it runs. The CAT clogged up and was told that is because of the poor running condition. I got a P1309 code and replaced the Cam syncronizer but it idles rough and when I drive it in OD it vibrates really bad. I am not getting any codes now but it seems like a miss on one or more cylinders. I have replaced the MAF, Idle solonoid, both O2 sensors. After my wife drove it today I'm getting a P0402 and aP0171. I just replaced the EGR valve. Any ideas?
Thanks!