[KeithO]

My wife's car (1995 BMW 525i) has been slowly losing power and having reduced fuel economy over the last 18 months. I rarely drive the car. 2 years ago, it got about 32mpg on highway trips. Yesterday, I drove it for about 150 miles and only got 25-26mph.

It is down on power and very occasionally smells like a morning-after Guiness-fart. I am 90% sure that the cat is shot. I priced OEM replacement cats and every source I checked was in the $485-$500 range (yikes!). There is also the obvious choice of getting a universal cat and making it fit...

How can I be absolutely sure that this cat is bad? I'd like to be completely sure before I commit the time and potential effort on this.

Thanks

[231go]

Never used the seafoam, always used the GM top engine cleaner. But thats only because my dad is a GM employee and he brings that stuff home by the truckload...along w/ brake cleaner. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif) But its does the same basic thing. Just shoot the stuff down the throttlebody while you rev it up and use the entire can of it. Then take her out and flog it aroung w/ it locked down in a low gear to maintain higher RPMs, then change the oil when your done and hold off on the plugs until after you do it and you will be fine. Start w/ the cheap maint. stuff before you go dropping the big bucks on a "shot in the dark". BTW 500bones is about what GM wanted for a SINGLE converter on my 96 Camaro....