smoke after new cat and o2 installed - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

eerrrrr · 01-22-2008, 09:38 PM

91 w/ 98 ka24de (<--supposedly) w/ all s13 stuff (using s13 maf and stuff). auto to 5spd. only mod to engine is walbro 255 pump.

so dealing with this smog thing i have, i went ahead and installed a new o2 sensor (universal one that i crimped to the stock end--bosch instructions), drove around for a minute then came back home. then went and installed the cat. well after i installed the cat, i noticed it was smoking during idle (didnt do this after the o2 install or before). it was fully warmed up (because i drove it back from the muffler place). it was cold, but not cold enough to see your breathe. not sure if this is normal or anything, but it hasnt done this before, so im just really paranoid now (dont want to keep dumping money left and right). ill post up tomorrow with what color the smoke is and how it smells.

tt99ol · 01-22-2008, 09:48 PM

its probably condensation as the cat converts hydrocarbons to water, get an adjustable fuel pressure regulator to go with that 255lph, it makes you run too rich

g6civcx · 01-23-2008, 11:06 AM

Give it a few days and see if it stops smoking. Normally new exhaust parts will smoke a little bit when new.

*brndck* · 01-23-2008, 11:18 AM

most likely its just residue on the cat. often times new exhaust components will smoke for a while after install (usually a few hours or so). if its still smoking after a few days then i'd be concerned.

Dream240 · 01-23-2008, 11:21 AM

Every CAT I've ever installed, smoked for a bit after install. It's just the converter breaking in, kinda like new brake pads. Remember the CAT gets really hot. Prolly burning off any stickers or packaging crap that got stuck in the openings during shipment. My old CATCO had stickers on it that just burned off after install, little smoke...no biggie.

Plus since you install a walbro, you're running even more rich then a stock FPR, so you're getting alot more fumes coming out the exhaust. Be sure it's not exhaust fumes coming out of a leak due to the install.

Fresh gaskets? new mounting bolts?, CAT mounted in correct flow direction?

eerrrrr · 01-23-2008, 02:09 PM

ok smoke kinda dies down. but smells like rotten eggs. but yeah how much richer am i running? maybe this is the case why im failing smog at idle (running too rich = high HC??)

Dream240 · 01-23-2008, 03:15 PM

*quoted from autorepair.about.com*

Quote:

There Is A Rotten Egg Smell Coming From The Exhaust:
Whenever you run the engine and are not moving, you notice an awful smell from the exhaust. The smell is like that of rotten eggs. Not only do you notice this, so does everyone around your car. You may also have noticed that your gas mileage has been worse lately.

Possible causes:

There is a problem with your electronic engine control system: Scan injection and emission control system for Diagnostic Trouble codes. Replace or repair as required.

The ignition timing may be set wrong: Check and adjust ignition timing.

Your fuel pressure regulator is bad: Replace the fuel pressure regulator.

The engine may have mechanical problems: Check vacuum lines and fittings for leaks. Check engine compression. Check for broken fittings and mounts.

The engine is running too hot: Check cooling system, thermostat and cooling fanes for proper operation.

So judging from your comments, you prolly have a bad FPR due to installing the Walbro. Sometimes a slightly faulty FPR will go out when pushed, ie. the Walbro, I would go with a Nismo FPR and a fuel pressure gauge install to monitor.

tt99ol · 01-23-2008, 05:52 PM

change the fpr, a walbro raises the static fuel pressure by .5 bar wchich is alot more than the ecu can compensate for, nismo adjustable and a gauge will fix it

sideways7 · 01-23-2008, 07:08 PM

[quote=eerrrrr;1785729]ok smoke kinda dies down. but smells like rotten eggs. quote]

Lol. Last time I got a new cat it smelled like fresh pretzels. But yeah my car smoked a little while idling until the cat broke in.

joshchewuhh · 01-23-2008, 07:18 PM

mmmmmmmm rotten egggs

eerrrrr · 01-23-2008, 07:34 PM

ok i had a feeling i was going to need a FPR...well here i come. next week though cuz im broke as funky sheets right now.

01-22-2008, 09:38 PM	#1
eerrrrr Zilvia Junkie Join Date: Dec 2005 Location: FRESNO, CA Posts: 531 Trader Rating: (1) Feedback Score: 1 reviews	smoke after new cat and o2 installed 91 w/ 98 ka24de (<--supposedly) w/ all s13 stuff (using s13 maf and stuff). auto to 5spd. only mod to engine is walbro 255 pump. so dealing with this smog thing i have, i went ahead and installed a new o2 sensor (universal one that i crimped to the stock end--bosch instructions), drove around for a minute then came back home. then went and installed the cat. well after i installed the cat, i noticed it was smoking during idle (didnt do this after the o2 install or before). it was fully warmed up (because i drove it back from the muffler place). it was cold, but not cold enough to see your breathe. not sure if this is normal or anything, but it hasnt done this before, so im just really paranoid now (dont want to keep dumping money left and right). ill post up tomorrow with what color the smoke is and how it smells.

01-23-2008, 11:21 AM	#5
Dream240 Nissanaholic! Join Date: Dec 2002 Location: Inland Empire, California Age: 42 Posts: 2,188 Trader Rating: (8) Feedback Score: 8 reviews	Every CAT I've ever installed, smoked for a bit after install. It's just the converter breaking in, kinda like new brake pads. Remember the CAT gets really hot. Prolly burning off any stickers or packaging crap that got stuck in the openings during shipment. My old CATCO had stickers on it that just burned off after install, little smoke...no biggie. Plus since you install a walbro, you're running even more rich then a stock FPR, so you're getting alot more fumes coming out the exhaust. Be sure it's not exhaust fumes coming out of a leak due to the install. Fresh gaskets? new mounting bolts?, CAT mounted in correct flow direction? __________________ Don't mess with my monkey...he's loaded.

01-23-2008, 07:18 PM	#10
joshchewuhh Post Whore! Join Date: Jan 2007 Location: brocal! Posts: 3,681 Trader Rating: (56) Feedback Score: 56 reviews	mmmmmmmm rotten egggs __________________

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01-22-2008, 09:48 PM	#2
tt99ol Zilvia Addict Join Date: Jan 2005 Location: quartz hill CA Age: 34 Posts: 644 Trader Rating: (8) Feedback Score: 8 reviews	its probably condensation as the cat converts hydrocarbons to water, get an adjustable fuel pressure regulator to go with that 255lph, it makes you run too rich

01-23-2008, 11:06 AM	#3
g6civcx Post Whore! Join Date: Apr 2004 Location: Virginia, USA Posts: 5,764 Trader Rating: (5) Feedback Score: 5 reviews	Give it a few days and see if it stops smoking. Normally new exhaust parts will smoke a little bit when new.

01-23-2008, 11:18 AM	#4
brndck Premium Member Join Date: Jun 2003 Location: torrance, ca Age: 39 Posts: 12,407 Trader Rating: (129) Rides Gallery: brndck Feedback Score: 129 reviews	most likely its just residue on the cat. often times new exhaust components will smoke for a while after install (usually a few hours or so). if its still smoking after a few days then i'd be concerned.

01-23-2008, 02:09 PM	#6
eerrrrr Zilvia Junkie Join Date: Dec 2005 Location: FRESNO, CA Posts: 531 Trader Rating: (1) Feedback Score: 1 reviews	ok smoke kinda dies down. but smells like rotten eggs. but yeah how much richer am i running? maybe this is the case why im failing smog at idle (running too rich = high HC??)

01-23-2008, 05:52 PM	#8
tt99ol Zilvia Addict Join Date: Jan 2005 Location: quartz hill CA Age: 34 Posts: 644 Trader Rating: (8) Feedback Score: 8 reviews	change the fpr, a walbro raises the static fuel pressure by .5 bar wchich is alot more than the ecu can compensate for, nismo adjustable and a gauge will fix it

01-23-2008, 07:08 PM	#9
sideways7 Zilvia Member Join Date: Jun 2007 Location: So-cali Posts: 155 Trader Rating: (0) Feedback Score: 0 reviews	[quote=eerrrrr;1785729]ok smoke kinda dies down. but smells like rotten eggs. quote] Lol. Last time I got a new cat it smelled like fresh pretzels. But yeah my car smoked a little while idling until the cat broke in.

01-23-2008, 07:34 PM	#11
eerrrrr Zilvia Junkie Join Date: Dec 2005 Location: FRESNO, CA Posts: 531 Trader Rating: (1) Feedback Score: 1 reviews	ok i had a feeling i was going to need a FPR...well here i come. next week though cuz im broke as funky sheets right now.