Exhaust Smells Rich

[Just a Six?]

I wanted to start this thread so I can keep adding to my progress as I go along.
In the last 3-4? seasons I've been chasing (with not much effort) the reasons behind my gassy smelling exhaust. The engine has maybe 40-50 track runs & not too many street miles since the last rebuild about 7-8? years ago. TT 6.1 2009 chip with a/f tracking, burned for 26 lbs but my waste gate rod set at 22 lbs, 60's, Gen 2 translator with 12% fuel out across the board,
(I can do low-med-high load rpm points later) fuel pressure turned down 1 lb, old 67 Q trim
4" in 3" out, power logger, wide band, scan master, fuel pressure gauge, Meth etc.
I purchased a Bob Bailey Gen 2 chip with the Gen 2 originally years ago & used it a month then back to the TT but tried it today & black smoke with bad stumble at idle?? Back to the TT
One more try tomorrow & if no good I'll send it back for Bob to look at.

1 TT chip I did a 10 min city cruise BLM part throttle 122, coast 128, stop light 137
I'll get the PL hooked up for a good run Sat am early but for now
2 compression check all cylinders from 146-150
3 all plugs are White & gap stayed at a tight 30 thous.
4 PCV is nice & clean
5 small oil filter to Turbo is clean & that's where I stopped today. PL in the AM
Maybe my imagination but seemed a bit less gassy smelling at idle?
 

[1KWIKSIX]

Hi Dave,


I've also got the Gen II Translator and wide band with PL.



Hmmm, that's strange. I ended up going to Bob Baileys' Extender Extreme chip cause I found the Turbo Tweak chip extremely rich and car billowed out black gobs of carbon on my garage floor while warming up and idling.
So I changed over to Bob Baileys chip and problem solved.

[Steve Wood]

Do not go by your nose.....prett y much useless

Go by the O2 readings and/or your wideband.

Also remember that idle is not indicative of part or wide open throttle conditions.  Plugs say you are good from what I can understand.

[Just a Six?]

Steve I'll get some logs & the plugs looked good so I'm confused with this but when we get together driving to the car show or a cruise whoever is behind me on the hiway always tells me the exhaust really smells like gas & some to the point of rolling up their windows.

[Steve Wood]

Is the cat converter on the car in good condition?

[Just a Six?]

Funny you mention that since I Never ran a Cat until the last engine install & I never had this issue back then. It's a used 3" high flow & it has 2-3 large holes poked in the screen or honeycomb with a big screw driver or similar. This is also when I added the 60's & Gen 2 but I bet the Cat is suspect? Maybe time to yank it off & see what I have going on?
 

[Steve Wood]

Yeah

[Just a Six?]

Steve finally after 7 years of smelling like gas when parking the car in the underground it's fixed! There was a lot of Carbon buildup from the turbo to the Cat & some past it but not as bad.
I ASSume that it caused back pressure which caused the Carbon but not sure I fully understand why it causes it to smell like gas? It also feels smoother & a bit louder. The wife is going to be Happy!
I'll still get a new Log to look at if it's nice Sunday or Holiday Monday.
Man I went to BPG & raced like that & still pulled off an 11.20 in the noon day sun so this should help that cause if I ever get out again. My left foot is numb & my back & neck hurt like heck but it was worth the pain & suffering! Thank God for the band clamp I used on the connection as it really made doing the job at home possible & without too much frustration.

[Steve Wood]

From the numb feet up, you and I must have related backs.

I have noticed that they smell differently with good cats, bad cats, and no cats.  Maybe it has something to do with the modern gas?  They should smell richer than modern cars when we run open loop idles and richer than normal due to the cams, etc.  If the wife is happy, to heck with the people following you! 

[Just a Six?]

I went for a drive up the 401 & 400 hiways & did two 4-5 sec blasts from about 50 mph. I guess the wide band needs a Free Air since I took out the sensor from DP when I pulled it but SM read 760-770's & no fuel haze out the pipes & no gas smell when revved up a couple times when I parked it. My TPS needs adjustment or I wasn't quite full throttle as the highest reading was roughly 3.55-3.60 It's quite possible my foot wasn't all the way down since it's a hiway & I get nervous doing blasts because the car hits up near 100 mph pretty quick. Steve I'm really happy that you suggested the Cat as I needed the push to get back working under the car & the Cat had crossed my mind long ago but I just wasn't sure the work was worth the effort if I was wrong so I kept looking at the chip & Gen 2 settings. I had a lot more faith the Cat was the problem after you suggested it. That's why I jumped on it the next morning after reading your post so a big Thanks for the Motivation! Cheers!   

[Steve Wood]

 

[Scoobum]

Dave...remove the Gen 2. It doesn't work worth a shit...hence why it was discontinued.

[Just a Six?]

Brad I would but then I need some kind of Translator for the 3" MAF

[Scoobum]

All you need is a regular Translator...a nd whatever MAF you want. LT1. LS1...or Z06...tho the Z06 requires a 3 to 5 pin connector. We've removed several Gen 2's and the cars have run mint with the TT chip.

[1 RARE T]

Confused.


Plenty of guys run no cat and yet don't have a raw fuel smell.


Seems to me the fix is masking an overly rich condition.