My 98 Ram has seemed A little sluggish lately. Been burning a little oil due tp valve stem seals could that cause it. I've done plugs cap rotor and wires. Also I've done the plenum fix. Have a cold air on the truck but didnt seem to effect it when it was first installed. Sometimes when I first start the truck and drive a little it seems to wanna stall when I hit the brakes or switching from park to reverse etc. Could this be a clogged cat or bad IAC? Any help is much appreciated.

 

Give a bad plenum long enough and it will ruin the pre-cat O2 sensor and catalytic converter.

Probably wouldn't hurt to change those out in any event, even if it's not the problem, last I checked you can sell your old cat to http://www.sellyourcatsdirect.com/ for around $75, and they offer free shipping I thinks....

 

Does the symptom seem to disappear once the truck is warm or has been driven for a while? I fought this same battle with my truck 2 weeks ago. The upstream O2 sensor goes bad (doesn't always throw a code - mine didn't) and causes idling issues about 1-2 mins after start-up. I ended up replacing both sensors and throwing on a stainless steel direct-fit cat from flowmaster (which I highly recommend). Idling troubles gone, fuel mileage is also slightly increasing

 

Where did you pick up that cat? And what did it run you?

 

You can pick up a catalytic converter just about anywhere. Call some of your local parts places for prices. Check on ebay, amazon, many online retailers.

 

There's the flowmaster cat for your truck...they changed the exhaust style on 2nd gen rams in 2000 so 2000-2001 models like mine use a different part number. My flowmaster direct fit only cost $184 from amazon....i have no idea why the price difference is so big for two nearly identical products!

In any case, the quality is extremely good and there has been no heat shield rattling or leakage of any kind.