I dropped 300 on a new cat converter for my B250 today (ugh). My old one had metal and rattling around on the inside, and blew the smog pump pipe right off the side. Now, the van didn't run too bad with the older cat converter on it, but it was incredibly loud, stunk inside when at a standstill, and heated up the floors rather nice (on a 95 degree day, that's not fun).

Anyway, the muffler shop changed it out, but I'm beginning to think that may not have fixed my issue. For one thing, I've got a severe lack of power now. Any hill I come to is quite a task for the van to pull. If I drop the pedal it just hums and the engine races faster while decreasing in speed. At low speeds, none of this is noticeable and runs fine 1-30 mph, but any highway driving is a nightmare.

One thing I noticed is that the converter they put on looks a bit smaller than the original one I had on it. I'm wondering if they have the wrong kind on it. The muffler itself looks like it was replaced sometime during the van's lifetime. It's not nearly as rusted as the rest of the exhaust system, so I doubt that it's clogged.

So I suppose my questions are:

Could the muffler itself be clogged? As I said, it doesn't look old, and most of the people I've talked to said they rarely do clog.

Could the shop have installed the wrong kind of cat converter and is limiting it?

Could this be some weird issue with the smog pump?


Thanks

 

Based on the information you have provided, this is too small and constricting your exhaust flow. This will kill your acceleration and your gas milage.

 

The standard test for a restricted exhaust system is to remove the front O2 sensor and see if the vehicle drives better. If so, our suspicions are confirmed and I would insist that the shop replace the convertor with an appropriate one for this application.

 

Alright, the problem turned out to actually be the muffler itself. The cat converter was shot, of course, but apparently some debris from it got into the muffler and clogged it up. All together, it turned out to be a $400 fix, but at least I've got a new exhaust system.
It runs great now; I never realized how much power these vans really had.

 

Glad you got it sorted out. When I tossed the my rusty OEM muffler and upgraded to the Walker Sound F/X I was very impressed at the difference it made.

Given the torque and the low gearing these vans are a lot of fun to drive. I have no problems leaving your average pony car in the dust. Which is quite upsetting to some of them!