Well, my car suddenly started making a sound like if the catalytic converter was removed, which it has not. The noise started when my husband connected the a/c compressor directly to the battery because it didn't turn on automatically when we turned on the a/c on the dash. So, yes the compressor is on all the time until it gets fixed and we already know it is because of a bad transducer. So, with that said, is that why my car sounds like it has no catalytic converter?

  • Hard wiring the ac compressor is a bad idea, more than likely it is the compressor making the noise. – Moab Apr 12 '18 at 20:08
  • Welcome to Motor Vehicle Maintenance & Repair! What you are describing is very subjective. Really, a car doesn't sound too much different without a cat than with a cat, if all else in the exhaust system stays the same. Are you just saying it's "louder" than before? Maybe give us a little more information? Are there any dash lights? Also, plugging the A/C compressor clutch directly into the battery is a BAD choice. Great way to destroy the compressor. – Pᴀᴜʟsᴛᴇʀ2 Apr 12 '18 at 20:09
  • As you have not mentioned your car, it could be the compressor itself making the noise, in most dated cars you can hear from inside the cabin when the compressor turns on and off. – Nilabja Apr 13 '18 at 11:33

I would start by getting down low/underneath it, on a cold start and looking under the car to see if there's a visible exhaust leak.

Have someone rev the engine a bit, and see if you can see any puffs of smoke.

Shining a flashlight on the likely areas can sometimes help, as well.

If the sound isn't as extreme, it might have something to do with an air silencer in the air intake "System". There's a possibility it was jostled out of place during his working on the vehicle.

I hope this helps.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.