WTF My Car Smells Like Fireworks....

[rsmithdrift]

Ok my car runs GREAT! Better than it's ever run before since I've owned it. It's a 93 240sx btw. The past two years it's run 5:1 a/f rich and 25:1 lean back and forth and hasn't had any power would plume black smoke while idling when rich wouldn't accelerate when lean (had a bad fuel pump) and I finally fixed the damn thing.

But now ever time i hit the gas I smell fireworks... like gunpowder. My car runs on gas not gunpowder... idk what the f*** could cause that smell. I have a magnaflow hi-flow cat that I've had for about 3 years. I passed emissions last year when it was running lean but I failed it now that the car runs right... way high HC and CO. Twice the legal limit.

WTF?? Could my cat have gone bad because of it running so horribly the last couple years and smell like that??

[sx moneypit]

The reason it smells like that is because it is running too rich. Rotten egg smell, right?

[rsmithdrift]

No it smells like straight gunpowder.

Like if I got a bunch of fireworks and set em off that's what my car smells like.

And I know a rich smell it smells like unburnt gas... this isn't like that it's like ... gunpowder. idk what else to tell you.

[sx moneypit]

Gunpowder,rotten egg smell, it doesn't matter.It smells that way because of the reaction in the catalytic converter.What is your CO and HC readings?

[rsmithdrift]

HC 316 CO 2.2%

AFR gauge shows idle between 11:1 and 13:1 WOT it's about the same. cruising it reads ~14:1 It's a new 02 sensor also.

[rioredstang]

What is your coolant temp. showing? If its a little low that could drive it rich. Do you have EGR valve on engine? A leaky EGR valve will give funny smell and Hi HC & CO. Make sure idle speed is up to spec. I even raise idle up to 1100 to 1200 rpm to clean up readings. I do emission repairs in Chattown all day long.

[rsmithdrift]

Dude you never did tell me where your shop is. I sent you an email to ask but you never replied. lol.

My emails [email protected]

Let me know where your shop's at and I'll bring her on by. I tend to think it's my cat. I passed last year running 7:1 afr lol. And I don't have any egr system and haven't had one for years lol.

[rioredstang]

I didn't see email. I sent the address to your email.