I have a 1996 5.9 1500. Every 2 months I have to replace the spark plugs. Twice so far the dealer has done this. The truck runs like crap; stalling, rough idling, surges etc. I was told that a bad catalytic converter can foul the spark plugs. I have never heard of this and it sounds ridiculous. Does anyone know if a bad converter would create the symptoms I listed? Thank you.

Syl

 

no, sounds rediculious if a cat is bad you will either have too much backpressure or just dirty exhaust.

I would suggest finding out what is really causing the problem... how old are the cap/rotor/wires? you should use a good brass cap & rotor and good wires such as MSD 8.5 superconductors.

do you use oil? the plenum gasket is something that is a common failure on the magnum motors. if it's leaking, you will get pinging, oil on the plugs next to the leak (in sever cases).

also, with regards to your surging... depending on when it does it, your TPS could be noisy causing the surging. also the TC will lock and un-lock at freeway speeds...

 

Cap, wire and rotor are 3 months old. Everytime I bring it into the shop they change them. This has happened twice in the past 5 months. They change the wires and the plugs and it runs fine for about 2 months. Then the service engine light comes on again, it hesitates on acceleration, rpm surges at idle and it stalls at lights. But once the plugs are changed it runs fine again. The engine sounds strong. There is no pinging or knocking. But in the later stages of this 'problem' on hard acceleration it sounds like acceleration in neutral...there is no power, just a high whining acceleration sound as if you had the thing in neutral and pressed down on the gas. Eventually, it will be impossible to start until the plugs are changed again. 2 months later the problem will come back.

 

listen to steve, he knows his ****, and hes helped me out a lot. we just got our plenum gasket set that he recomended to us, and my truck is no longer stalling at all, and we cleaned out the throttle body really well, and she runs like a champ now. Dodges are tempramental beasts. if its not one thing its another, and stop taking it to the dealership thats why your still stuck with this problem. they are trained to keep selling you stuff. And i speak from personal experiance. when my 02 sensors were bad he was trying to replace all three of my cats, at close to 400 a pop.
you would know if your cats were bad anyway.. a huge loss in power, if you looked at it, it would be red, and smell really bad. i had an 84 suburban before my 2000 ram 1500 4x4 5.9L QC. and my suburban had a cat problem like it was cool.. really go through your truck, and look at what steve is telling you. hes helped me quite a bit with my beast, and she runs like a champ at over 140K miles now.
have a good one, and good luck with your truck.
shannon

 

Actually, if a converter is plugged you will get driveability problems (rough idle, poor acceleration, surging). I see it all the time on Grand Prixs with plugged converters. It's also a problem with the v10 Rams. I dunno if it would foul out spark plugs though. Unless you have an o2 sensor behind the converter, and the pcm is richening the mixutre because the converter isn't functioning properly.

I dunno how many miles your truck has on it, but it's almost 10 years old. It might be worth checking the converter. And if you DON'T have a sensor behind it, you can just chop the converter out and put in a straight pipe and see if the problem goes away. That's not emissions legal though, so if you live in an area where that is an issue than that solution would only work for "testing" purposes. You would have to install a new converter if that is the cause of the problem.

 

my dads truck was doing almost the extact same thing, ( its a chevy sub. ) we took it to a friends shop to look at it and he couldnt find the problem. we changed plugs every two months too. This is what your not going to want to hear. he pulled apart the hole dam fuel system and found that the fuel rail was rotting away and filled with little metal chips. the fuel filter and the gas tank were also filled with the. my guess was it was from a gas station with bad tanks. I dont have a clue in hell how all of that crap got past the fuel filter. the hole thing cost us like 2,000.00 even when he nocked have the price off. Has this happed to anyone elts before?

 

I had a tractor do that once.

The fuel filter sediment bowl filled up on me about a dozen times in two days.

Took the tank off and to a radiator shop for cleaning and it fixed the problem.