Its better to start your own new topic on your issues. The guys here are incredibly helpful and having everything in your own thread will assure you get all your issues addressed and properly.

Its different, i know. Most forums hate when people start new topics expecting you to dig thru years and years of previous threads before you make even a peep. I think were lucky to have this kind of "community" here.

 

I wasn't talking about the year of the car, I meant the age of the the original post here. You had basically added your (mostly unrelated) question onto the tail end of a 10+ year old post.

There are some potential issues in doing that:
-Some people opening the thread wont even make it all the way down to your question as its nearly 20 posts down
-People who do open it and start reading often reply to earlier posts, causing your new post at the bottom to get buried in the conversation.
-Lastly the thread title isnt necessarily applicable to your situation, so the kind of people who open a thread about exhaust parts may or may not be familiar with your general drivability issues.


It was just a suggestion to help you get better visibility/ responses.

 

I am on a football forum, and you get your butt lit up for starting an identical thread. I am new here. Thanks for the advice.

 

P0420. Had it. Replaced downstream o2 sensor. Worked good 2 yrs, came back. Kept resetting till it was once a week. Replaced upstream sensor twice, 1st was bad from stock. Worked good 6 months came back again. Couldnt get downstream out again. Replaced downpipe assembly and both sensors. Good ever since. Best to replace 02 sensors in pairs so readings wont b altered by senaor degradation(opinion). Downpipe was 350 from,advance think it was ...cant remem.

 

I'm having problems on my 2000 3.8 when you go to accelerate the car instantly loses power or it sounds and feels as if it's choking/ there's no acceleration only if I lightly give it gas I can get it up to speed, I'm jus wondering if it's definitely my converter and resonator that's giving me this stress.

 

Could be a fuel delivery problem, or a stopped up converter. Coil packs are known to go bad on 3.8s, but are cheap. Sitting at an idle, can you rev the motor without it being under load? A good mechanic can check fuel pressure, and your downstream 02 sensor should be telling you if the air/fuel ratio is not correct. You can always try a bottle of Catclean, about $10 in a silver container.I also run Lucas gas/injector cleaner treatment in everything I own about every 4th tank. Stuff works.

 

As with a poster above, I'd suggest starting a new thread rather than tagging on the bottom of a 15 year old thread. A lot of people won't make it this far down a thread to read about your issue.

With that said, no one can tell you definitely what your issue is with the extremely limited data provided. We'd need you to perform some diagnostics to gather data to help us get to a conclusion.

I will say a resonator plugging up is nearly impossible (unless your cat physically came apart inside and got trapped in the resonator). I suppose one could rust out and collapse in theory, I've just never seen one do that on a w body (without the exhaust rusting a hole somewhere else first showing that the system was done for).

The cat can certainly fail and plug up. Ive had one do that on my 03 Impala around 100k miles. One easy way to check for a cat failure is temperature. Cats get hot in the body during use but are usually fairly even in the piping before and after if things are flowing well. When a cat gets plugged up, it'll be cool after the cat but the piping up front will get very hot due to the backup. On my failure the inlet pipe was just glowing red enough at night to visibly see after a gentle couple laps around the block.

There's probably some 'typical' temperature delta you can find online, but it'll be an obvious/ alarming delta if its plugged. Id start by measuring that if its your main suspect as its quick and easy.