i have an 03 cherokee i put a new fuel pump in but still after it has ran for bit it starts to run crappy also right were the exauhst pipes hook up to the manifold turn cherry red, could the converter be plugging up and causing my problem ???????

 

I've seen the "glowing exhaust pipe" syndrome several times, but usually it was on older designs. Essentially what you have is a situation where the exhaust valve opens before the combustion has finished - this lets the combustion continue through the exhaust port into the manifold & exhaust pipe. The conditions under which this can happen are usually generated with really bad timing where the spark is heavily retarded (it could also happen if you have really bad exhaust valves). That having been said, we need more information to really get to the root of your problem - here's what I'd like to know:

• Which engine do you have (is it the old in-line 6 or a V)?
• If it's a V, do you get the glow on both sides or just 1?
• Has anyone done any timing work on this engine?
• Has anyone ever removed & re-installed the cam sensor housing (on Chrysler engines of that vintage, they had the bottom half of the old distributor that was left in the design - this is where the cam sensor was housed)?
• Does the engine back-fire through the throttle body when it's under load?