Hello all. I am new to this forum and to Dodge Trucks in general. I have just obtained a 2001 Dodge 1500 club cab 4x4 with the 5.9L engine. I got this as strictly a weekend hunting and fishing machine and as far as I can tell it is strictly stock. It was misfiring on 1 and 8 when I got it and I did a tune up (plugs, wires, dist. cap and rotor) and thought that would clear it up. Nope!!! I am now running injector cleaner in the hopes that it is a couple of clogged injectors. I have tested compression in all the cylinders and all have good compression. Should the injectors not be the problem, what are your suggestions? The misfires seem most pronounced at idle and the RPMs do not fluctuate very much at all so I do not think that it is a crankshaft position sensor. I am hoping it is not the PCM computer. Maybe the cat converter clogged? I have next to nothing in this truck at this time (a long story) and do not mind spending a little to get it running smoothly because everything else seems to work great. Thanks in advance and look forward to trading info with you all.

 

Also try this. It isn't supposed to apply to 2001 model years like yours and mine, but ya never know. Its free and takes just a little bit of time.

TSB 18-48-98

Otherwise, yes, I'd get the converter checked out. You can test the injectors really easy as well, take a multimeter, set it to ohms, and put one probe on either pin (there are only two) after removing the injector wiring harness. It should read 12-13 ohms when cold.

 

a clogged cat will give you misfire codes and i think o2 sensors will also. get a heat gun (20$ at advance) and check the cat. the front should be 4-500º and the back should be 50-100º cooler but if its 600º in the front and like 100 or 200º in the back then its plugged. you can also stick your hand in front of the exhaust pipe first to see if it has a pretty good flow. the cats on our trucks are a common failure point. a lot of guys on here really like the magnaflows, they are 72$ on summitracing.com for a universal and about 200$ for a direct fit. if you're lucky it'll be the one in, one out style so you can get a universal fit. if you do get a heat gun you can check some other things as well just for piece of mind like the transmission, it should be below 175º and the radiator and its hoses. and the transfer case, and u joints (after a drive they should be just barely warmer than the outside temp, if they are hot then there is no grease in them and they need to be replaced)

 

2001s have the single 3" inlet/single 3" outlet converters.

 

Thanks for the suggestions so far guys. I will let you all know how this goes.

 

OK. The cat is good and I am still running the injector cleaner as I will only drive this truck on weekends for the most part and have not yet given it enough time to do any work. If there is no improvement, I will pull injectors and inspect them. I am also going to check the intake gaskets and plenum plate for leaks as I believe that could be the problem. I guess while I am at it I will check or replace the Crank Position Sensor and maybe the cam position sensor, although I would think that those would throw random cylinder misfires and not the same two cylinders all the time. This is not a dead miss but more like a lean condition misfire. Any other suggestions appreciated. New to dodge and to this particular truck. thanks,

I forgot to add that when I added the injector cleaner, I reset the codes and while the truck is still misfiring, it is no longer turning on the CEL. I have not checked for new codes without the CEL light on. Thanks,

 

How did the cat get tested?

 

First I tested the cat by the good ol' rattle test which it passed, then I got a muffler shop to test it by putting a probe in the cat which it also passed. I was glad not to have to make an outlaw of myself by a cat delete (no emissions testing in Alabama yet) and real glad I did not have to shell out the $$ for a new one. I would have to pay for that labor as I have no welding skills at all.

 

I don't know how accurate the probe is going to test it, it needs to be pressure tested.

 

Zman I must confess to not watching the muffler shop too closely. All I know is that they hooked up or put something in the cat and when I returned they were able to tell me that the backpressure was OK. I am not getting any power loss just the misfires on 1 and 8. I do know that if I don't get this figured out I will have cat trouble because of the unburned fuel getting into the cat. So I may end up with it anyway. It is back to the shop on Monday for full blown diagnosis. I really suspect a intake gasket leak or some other vaccum leak or (if I am lucky) faulty injectors. If it is the intake gaskets I am going to go ahead and replace tstat, water pump, and plenum pan (with the Hughes replacement) and get it all over with at once.