i just bought a 98 ram 5.9 4x4. i put new plugs, wires, cap, roter, and plentom gasket on it. still have a ping. also i was going up a hill the truck kicked into passing gear and it backfired and started missing. but when i let off the gas it staightened up. two questions. does it have a knock sensor and why would it backfire and miss under load?????? also i put on a cold air intake and flowmaster exaust. i read on here after doing upgrades you have to reset the computer. is that true and if so how do i do it..

 

No knock sensor.
Backfire could be caused by a lean fuel condition.
Search "plenum gasket". Yours is likely blown and causing an internal vacuum leak.

 

Be sure the wires on the cap are secure. That is a tight area back there.

 

A clogged catalytic converter can cause a backfire under load and generally sluggish performance.

 

got a code today. #8 cyl. missfire. took plug out and moved to #2 to see if code moves. either new plug is bad or new wire is bad. I HOPE.

 

where do you get these codes?

 

cyl 8 miss could be from clogged cat. if the plug is clean, and the wire is fine, check the cat for rattles.

 

Resetting the PCM is accomplished by removing the negative battery terminal for about 10 mins. Sorry I missed that Q earlier. The PCM will relearn the new settings, but if you've done a bunch of changes without a reset, it may be struggling to adjust to the new parameters.

You can also remove both terminals and touch them together and you won't have to wait, but just make sure that nothing from the POS or NEG terminals are still connected.

AFTER you get the cat checked and it checks out, try moving the #8 fuel injector to see if the miss moved with it. When you reinstall the injectors, make sure you lube the o-rings or they'll bind, rip, and leak fuel on the engine.

If so, you may have either a faulty fuel injector, or a dirty fuel rail.

 

I had this same condition after replacing the plenum gasket, plugs, and cat. Until I Threw tons of Techron plus at it and it stopped.You might have major carbon build up on the valves.

 

disconnecting resets the computer but how do you get the codes? One of those computer reader things you plug in?