Hey Scotty, love your channel. Ive got a 2005 Chevy Cavalier with a 5 speed manual. It has developed a popping from the exhaust at idle. It has a catalytic converter code that has caused the check engine light to come on. I was wondering if this could be related. I live in Tennessee so inspection is not an issue and I may decide to straight pipe the exhaust because I love the vehicle and hope to keep it for awhile. I'm just wondering what https://youtu.be/YvrnVl8aKNU the issue is. I've attached a YouTube video of the noise.
As Scotty has demonstrated in several videos, the active metals in the cat are in a honeycomb grid in the middle of the cylinder. Sometimes, the grid chips, breaks gets clogged. (Does the car ever rattle, as well, down there)? So, the cat might be clogged, it might be in the process of breaking down, etc. If this was the case, the exhaust would be restricted, and the choppy, chippy cough could be well be a sign of such partial blockage.
The relatively good news for you, I think, is that Cavaliers of that era have relatively inexpensive catalytic converters, if my brief google search is an accurate guide. So, yes, the sound and the cat code may definitely be related. The only way you'll know, for sure, is to take the cat off the underside and have a look at the honeycombed grid.
Sounds reasonable. Be glad not in Ca. State where all the auto parts are held for ransom requiring to pay for the 'priviledge ' of being blessed by the state. Heard it was something like $250,000 for a company to have ca give their stamp of approval for the catalytic converter. And its the same basic catalytic converter as any state. I got burned twice by that. My Chevy CAVALIER (1999) needed a new one because ran just above the legal limit. And it was gone. Put a new one on - costs me $100. . Passed easily. Then the two year period came back around. It passed but Suddenly that very SAME Catalytic converter I replaced two years earlier was no legal any more. Costs me another $500 for a catalytic converter I did NOT need. With the new 'ransomed' Ca approved catalytic converter, it passed. But it was worse polluter than the one I had on. Then it also happened to my 1994 Jeep Cherokee. Same thing. Passed no issue at all. But not the ransomed approved catalytic converter once again. New cat costs me another $500. And of course, passed but again it was WORSE polluter than the one that was replaced . So I ended up in the same year paying $1000 to replace the catalytic converters I did not need with the result being a worse polluter. Thank you bleeping idiots in Ca. So time to move I think. LOL
If yours rattles, it needs a new one. You might be able to just wiggle the catalytic converter or smack it and listen.