Stinky at Cold and Warm Start

[AZCreeker]

15 Suburban stock with 100k miles.
for the last 2 years truck stinks at startup.
doesnt matter cold or already warmed up start.
Smells like raw fuel.
got DI system cleaned, check and replace evap canister, checked for leak, look at fuel tables at an independent (unless he was not qualified and pretending to do so)
no engine light
all OX sensors have been replaced with oem new ones

I dont kjnow what to do anymore!

Anyone else?

Could it be cats even with no light on or since it smells like raw fuel it would be injectors related?

 

[OR VietVet]

You said you smells like "raw fuel". Have you checked for fuel leak?

 

[AZCreeker]

its coming exclusivly from the tail pipe, i have checked everywhere

 

[OR VietVet]

I think you have catalytic converter codes in your future. Or, fuel pressure regulator problems.

 

[Fless]

Get a scanner on it and read the long- and short-term fuel trims, at both idle and 1500 rpm. Post 'em up!

 

[Rygrego]

I had a similar issue and it turned out to be loose spark plugs. Not loose enough for a misfire or code.

 

[Miami-Dade]

its coming exclusivly from the tail pipe, i have checked everywhere

Do you smell it inside the vehicle?

I smell it ONLY outside the vehicle. That is even with the climate control on all the time on outside air. Some mornings when it is cold out it smells extremely strong. This morning was one of those days here in New York.

I am not concerned with it. Has been doing that since I bought it back in 2016 brand new. I figured DI has something to do with it. I have almost 120K miles on it now.

BTW I am living in a hotel right now and I smell the same thing from other late model vehicles in the AM.

Can not worry about everything.

 

[AZCreeker]

I hear you but its crazy stinky in my garage more than any other full size truck I ever had, I bet you are right DI or the nature of these trucks...
Not impressed but oh well

 

[Tonyv__]

Had my 15 for about a year and a half. Exhaust definitely stinks since I bought it . No codes so I just ignored it

 

[AZCreeker]

so thank you I am not crazy. I wonder if some ECU remapping could change that.
an exhaust shop told me they dont think its underperforming cats as if it was it would smell all the time. I am not sure about that.
I just did about everything you could do maintenance wise.
I work around heavy equipment and the big flat beds with the big lazy v8 on them smell way less than my little suburban
I just dont get it
Maybe someone know a ECU Tuning guru who could educate us on the nature of the bad stink?