Does My Chevy S10 Pick Up Need a Catalytic Converter?

Reader Question Thanks for the help on my other question…I have another: How can I test to see if my catalytic converter is clogged or bad and needs replacement in my Chevy S10 pick up?

Hey there Patrick

You can test for an exhaust restriction by having someone stand behind the tailpipe with a rag over the outlet of the exhaust pipe as you mash the gas pedal to the floor a few times. Warning, it will be VERY hot, do not burn yourself! If the engine RPM raises quickly and there is lots of hot exhaust coming out the tailpipe, you do not have a problem in the exhaust or catalytic converter system.

To be honest, you really need to have the computer codes read to help narrow things down…its cheaper than guessing at parts to replace and all the time involved in testing these items yourself. Do you have a local repair shop that is capable of diagnosing this type of problem that might work with you on price? When I owned my shop Thursday was the slowest day of the week….and I would usually discount our rates just to get people to come in on Thursday. You might make some calls and see if you can get a shop to cut their diagnostic fees for you.

You want the check engine light codes “Read”, but you really need to have the truck acting up WHEN the mechanic is reading the codes, since the light goes off when it runs good…chances are there is no negative information being stored in your computer at that time.

You mentioned previously that the check engine light comes on when it runs bad, and goes off when it runs good. You also said it ran bad/dies when the engine gets hot, which is probably due to a sensor overheating and freaking out the onboard computer.

Things that can cause the issues you describe:

1. Faulty MAP sensor – measures pressure in the intake manifold

2. Ignition module – controls spark to the plugs and the distributor

3. Camshaft and crankshaft sensors – if your model is equipped with them

4. Lack of fuel pressure – weak fuel pump

All the items above are fairly expensive to GUESS at. If you can’t make a deal with a local repair shop let me know and I will call my old shop (I sold it 6 months ago) and see if they will help you for a reduced fee.


Austin C. Davis

Looking for a Church Houston?

Posted in: Exhaust Smoke

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