1993 Pontiac Grand Prix catalytic converter

GAYCHI

MEMBER
1993 PONTIAC GRAND PRIX
6 CYL
AWD
AUTOMATIC
90,000 MILES

I took my car in to have a diagnostic done because I am having trouble with excelartion, my car hesitates when I am attempting to accelerate above a certain speed. Well they told me that the catalytic converter needed to be cleaned and that they would replace the two oxygen sensors afterwards and I needed a tune up, and that I needed some brakes in which the rotors needed to be replaced because they had rust on them. Something does not seem right about some of this stuff so I am trying to be smart instead of getting taking advantage of.

1 Reply

MMPRINCE4000

MECHANIC
8,549 POSTS

RUN from these dudes!

You cannot "clean" a CAT, you can put addiives in gas for cleaning fuel system but it would not clean the CAT.

The convertor will fail because of incorrect air/fuel ratio or an impact (running over a curb/hitting road debris).

If CAT is bad it will effect engine at all speeds if clogged bad enough.

Have fuel pressure checked with mechanical gauge, check spark with spark tester, also have ignition module tested at most autoparts stores for free.

The rotors will have rust on them, this is normal, it does not mean they need to be replaced, if rotors have groove marks on them you may be able to have them turned as long asyou stay within minumum speck.