Help w/Check Engine Light - Engine Codes

[lilngineer]

I am new to the forum and hoping someone can help...

We recently bought a 1996 Cabrio w/2.0L engine (165K) and the check engine light is on.

I went to AutoZone to have the codes read and are as follows:

P0422: Catalyst efficiency low-bank 1 - The PCM has determined that the main catalyst efficiency for bank 1 is below threshold for the current engine operating conditions.
P0102: MAP/BARO or MAF sensor condition - The PCM has determined that the mass air flow input is lower than expected for the current engine operating conditions.
P0172: Fuel trim bank one condition - The PCM has determined that during testing, the fuel system for bank 1 was too rich.

Does anyone know what might be throwing these codes? Are they common?

I reset the computer, but the light came back on. Any help is greatly appreciated. Thanks!

[drummerc89]

Do you hear any rattling underneath the car? If you do, the material inside your catalytic converter is probably falling apart, causing blockage in the air flow through the exhaust. Which causes back pressure and all the codes you listed. I just had this same problem a few weeks ago.


Check the cat. and see if you can hear anything loose in it. If you do, either break apart and clean out the material, or go the legal way and replace it.

fyi - if you just clean it out, you will still get the first code you mentioned because the O2 sensor will detect too much fuel because it is not being burnt by the now non-existing material inside. It will be fine though.