Hi All,

Sorry, the title should say "Need quick help".

The car is a 1990 300ce with about 200k miles on the clock. It's on its original catalytic converter.

I suspected that my cat was bad after I failed emissions, developed a rough idle and hesitation.

I suspected the cat because I previously have had to have my fuel distributor replaced, had fouled plugs and bad injectors, leak down, etc. Basically mechanics were scratching their heads trying to diagnose the rough idle after having tons of work done on it- they have either replaced or checked everything under the hood that they can think of. The list is seriously too long to list.

The last time I had it in, the mechanic suspected the cat, but he was very slow so I had to take my car back from him before he could test it.

I just took the car into midas this morning and they are saying it's bad. They tested it by doing a "heat test". They said a typical cat gets hot in the rear when its running. But they are saying mine is "ice cold" near the back indicating that it's not burning up the fumes like it should. I actually could have it backwards (could be cold in the front, hot in the back, not sure).

Not to be an a-hole, but I don't completely trust their diagnosis simply because they are midas. So here are my questions:

1) Is this a valid way of testing the cat? I know people typically do a vacuum test of some kind to determine if it's partially or completely clogged. I have also heard of mechanics simply disconnecting it and running the car to see if the symptoms go away. They didn't do anything like this.

2) They are saying that I can only get a "direct replacement" type of cat... meaning either OEM (no way I'm paying that kind of money) or another after market bolt-on version. They said they cannot use an generic one and weld it in. I have heard of others on the forums using universal ones though... The only concern I have with that method of replacement is that you have to put a lot more trust in the craftsman doing the welding and bending.

I ask #2 because they are saying it will cost $1,000 parts and labor for an aftermarket direct-fit unit. They said it's 2.2 hours of labor.

I asked them if they'd be willing to install one if I found a deal online and brought it in and they said yes. I'd rather not have to pay $1k. Their shop rate can't be more than $75/hr, so 2.2 hours should only cost around $170.

I found this cat that should fit my car. If I bought this one, the total with labor and shipping would only be roughly $450-$500. Any thoughts on this unit, or any other recommendations?

http://www.***************/carparts/mercedesbenz300ce19881989catcocat97171930.html

Not to rush- but I need to give them an answer in the next few hours.

Thanks!!

Peter