If anybody have any answers please let me know and much appreciated.. But I'm thinking it could be a bad Cat. But Im not really sure..

The simplest way to diagnose a clogged cat is with a vacuum gauge. Normal idle vacuum should be something like 14~20". If the reading drops precipitously as you slowly raise the RPM's toward 3000, the exhaust is obstructed.

An even easier method is to use a non-contact thermometer and measure the temps at the cat inlet and outlet pipes - the outlet pipes should be significantly hotter than the inlet if the cat is working properly.

What trouble codes are stored?

It was p1447 and like p0400. Also, thanks everyone for the answers and advices

A clogged cat could indirectly cause both of those codes. Purge and EGR are tied up together functionally on that engine. The engine will be down on vacuum and the EGR backpressure will read higher than normal with the exhaust obstructed. The ECM would probably misdiagnose it as a purge issue.

VStar650CL wrote: ↑

Sun Apr 10, 2022 7:38 am

A clogged cat could indirectly cause both of those codes. Purge and EGR are tied up together functionally on that engine. The engine will be down on vacuum and the EGR backpressure will read higher than normal with the exhaust obstructed. The ECM would probably misdiagnose it as a purge issue.

Thanks

I had these exact symptoms on my 05' Xterra, I know not the same V8 but pretty close kissing cousin and turned out to be 3 bad coil packs, which eventually caused my cat to fail. IF yours are original then it is time, make sure to get OEM quolity ones, if you find Hitachi those are the OEM. Don't buy ones sourced from China or Mexico

Alright guys.. Thanks for all the help and much appreciated. But, I got the old codes fixed and now have P1320. I've been trying to figure it out but can't seem to pin point the problem and my exhaust is still popping like a misfire or something, Geeeeez.. If it ain't 1 thing its another.!!!

Will help a lot in diagnosing engine and suspension problems.

P1320 is almost always from aftermarket coils or spark plugs, but it can also come from poor coil grounds. If you haven't replaced coils or plugs and the grounds test good, then at least one coil or plug is is bad (most likely a coil). If you have replaced them but used aftermarket parts, that was very likely a mistake.

Whats up guys, been a long while since I've been on here... But yeah, update on my ride. My car is still having problems, only codes I have now is P0300 Random Misfire and P1447 Evap Purge. So, for the P0300, I put in new coils and sparks. Also for P1447 I basically fixed, changed out the system and still have problems..
I just has a chat with a friend last night and he was telling me about, it could be timing belt too! If it isn't installed and aligned right.. I just recently changed out my serpentine belt too not to long ago..
IJDK anymore!

Please help guys

Your engine doesn’t have a timing belt, it has a timing chain.

First off, is it really causing that much misery in your day to day or are you just tired of seeing the CEL? These cars are old, most parts are hard to come by and if you're not resourceful enough its a PITA. Obviously we are an outlet but finding a local mechanic would be ideal. If not that, I would dump the car and buy a Camry or Accord. Just being honest.