'02 P5 Engine feels like it's surging. Any ideas?

[minerleague]

I have an '02 P5 with 128K miles that I bought new and it's been a very good car. For the past couple of months I've noticed what feels like the engine wanting to surge and then let off while driving at a constant speed, usually in the 40-70 mph range. I notice this more within the first 15 minutes of starting the car and driving off. I've never gotten a check engine light to come on and I don't feel this surging all the time. When the surge is letting off, it almost feels like a slight hesitation like no spark from the coil but coil packs, wires and plugs are new, thinking that this was part of my problem. I'm now thinking of possible catalytic converter issues? Not moving enough exhaust flow? Has anyone had a problem like this or have any ideas to possible culprits?

 

[minerleague]

Forgot to add another symptom

Another symptom I've had on my '02 P5 is what sounds like a rapid exhaust leak coming from the area below the passenger seat floorboard when I really romp on the throttle and load the engine to 5-6K rpm in any gear. Hope this gives a little more clue to someone.

 

[drgnzadiel101]

the only time my car does that is with my a/c is on. my compressor is hit or miss do to the switch malfunctioning so it sends mixed signals causing a on and off scenario . dunno if that helps


btw maybe your cat is clogged

 

[minerleague]

Re:

I know what you're talking about with the A/C and I've experienced that also. What I have now is a different surge and hesitation feel. The clogged catalytic converter is a plausible explanation, I think, due to the sound of a rapid exhaust leak when I really rev the car high in the rpm band. I'm guessing the amount of exhaust that needs to flow through but can't is finding another path out. Does this sound plausible to anyone else?

Thanks for the reply.