1990 240 very loud exaust

[WESIDE]

Sup fellas, I just replaced my timing chain about 2 months ago and then my cat converter bout 2 weeks after that. (Just a little history) Well recently my exaust has gotten real friggen loud. Like almost no cat or muffler. Couple of years ago at one time i had the muffler unbolted and raced it pretty hard and it was real loud.... but nothing like this... I have a magna-flow cat back exhaust and when I get into the high 3000rpm and up it sounds like a f----n jet is taking off. I know the sohc had high compression and maybe changin the timing chain had something to do with it??? Only mods I have are k&n pop charger and cat back exaust. Also I have owned the car for like 7 years now and it has never been this loud.... Can any one relate or have any input???? Thanks, Wes

[180fan]

have you checked for an exhaust leak?

[WESIDE]

Yep I checked and theres no leak. I remember like 2 yrs ago I had a cheap knock off exaust from ebay on there and within a week of the install I blew out the internal resonator. lol Got real loud then so I was forced to install the silencer... Ended up blowing out the rear weld on the muffler Maybe I just blew my cat out again or something....

[WESIDE]

Bump..... No one can relate????????

[180fan]

Check the noise dampening sections. Should look like large canisters along the exhaust.

[WESIDE]

Would a faulty functioning egr cause muffler and cat converter disentigration?? I always have to put on a new cat to pass smog... Nox is always through the roof. And if so... any suggestions.... The egr is in a fked up spot on my 240. ThxBy the way I dont think I have any noise dampening on my exaust. Goes headers to downpipe to cat to straight pipe and muffler.

[WESIDE]

Does a faulty egr create high head temp causing high nox???

BUMP

[WESIDE]

CAN I GET A BUMP UP IN HURRRRRRR

[180fan]

a bad egr will cause high nox. if it's sky high, there are other issues.

[WESIDE]

What other issues should I look into? Vacume, the black box(aiv?) valve, I really appreciate any input.

[mattscar]

hows da idling?

[WESIDE]

car runs like a champ. Idle is good. No motor problems what so ever except the smog issue every two years and the burn up of the cat and muffler... I am puzzled as well. It may be time to shell out a monthly payment toward the G35

[WESIDE]

Has anyone had any problems with the magnaflow? Also sometimes it backfires like a shotgun.

[180fan]

an EGR malfuncion will cause high NOx on Nissans. the popping can be coming from the removed AIV. the other thing to look for is an exhaust leak unless you've got an aftermarket exhaust. check the insides of the exhaust to make sure everything is in tact.

[Daotoad225]

I have had exaust issues for a while on my stock exaust, right before the cat at the flange. too much pressure popped a hole in the gasket to the cat. good thing i am replacing my whole exaust sys soon.

anyone know anything about Pacesetter headers?

[babowc]

if you're backfiring and eating up your cat and the likes,you might be running rich.. what are you getting per gallon?

[180fan]

pacesetter = paint going to flake off very shortly after you get em. The build quality from what I've heard isn't that great either. You can do a search for what people have to say about pacesetter, it's been a while since someone brought that name up so you might also want to check through the archives. People will spend the extra cash for the hotshot header instead of the pacesetter.

[WESIDE]

I get about 16 or 17 miles per gallon. Could having my air temp sensor unhooked do to my pop charger cause a rich air fuel mixture?

[180fan]

Not likely. I had those sensors removed on my old SOHC and was still getting 25mpg.

[ken240sx]

if you're runnning rich check your plugs and timing, but that shouldn't give you a biiig change in exaust sound.

and about pacesetter, i haven't heard any great reviews on them. but i've had them for over a month now and they still look fresh and they have decent performance...i'd say pretty average with most headers, they aren't anything special. buuuut their dirt cheap and i'm probably boosting soon anyways soo it was the most sensible choice for me cause i've got to get rid of them if i boost. but they work great for me.

[nissans13240sx]

did you check the pipe that comes out of the manifold that goes to the egr, i was driven the other night and the plug i made blew out, causeing my exhaust to be F***ing loud.

[ken240sx]

what did you use to plug it?I was gonna try to find a screw to fit mine but i never realized that the reason they put such a tight thread on those things is so you can't screw anything else in there. so i just got both egr holes welded up for 10 bucks locally.

[nissans13240sx]

to plug it i just used one of the line ends and crushed the pipe and welded the tip then. but i guess i didnt tighten it and it blew out when i was driven.