Rough idle, thumping sound from exhaust?!

[goofynick6]

Ok,
I may be a newbie here, but I'm on other msg boards and I'm familiar with how it all works. I did several searches about this topic and tried several things.

Here's the situation: My mother's 1996 4.0 X with 130k miles, atx, started hesitating, cel and what not came on..ford dealership as usual did jack squat.

I've since replaced 2 of the 3 o2 sensors(other is on order), cleaned the maf, the iac(which started humming AFTER I cleaned it out Then I put in a new air filter, accesory belt, new wires and plugs(father put them in and don't know if he gapped them, prolly not cause I wasn't there). It's idling around 1000, the motor shakes a tad, and when listening to the exhaust it's a constant chug chug or thump thump.

Possible probs? And please suggest sites to get parts from as well.

IAC Valve
Spark Plug Gap
Plugged catalytic converter(s)
the other o2 sensor
Crank sensor
Others????


I wish I could check the codes, but not sure how.

Help is very much appreciated as this is getting annoying just replacing and not getting any better.

Nick

 

[yob_yeknom]

Take the truck to Autozone and they'll check your codes for free. Then let us know from there.

 

[aldive]

I would scan the codes before doing anything wlse.

Good luck.....

 

[goofynick6]

Well, does Advanced Auto do it too? I have no autozone in the area..just NAPA and advanced auto and monroe.

Thanks,

Nick

 

[fastcougar]

Pull all the plugs and gap them between 0.054 and 0.050 ... I had the same problem trying to fix a stumble at constant RPM between 1200-1800 RPMs. Turned out my #1 plug was smashed shut ... 0.000 gap . A regapping of all the plugs solved both problems