Tonyrodz's Tahoe Build Thread

[Scottydoggs]

bad o2. or maybe a injector is leaking. but when one of them stick open you see a -22.

 

[Fless]

I won't be able to look at it until this weekend. What could cause those fuel trims to be so off? Air/gasket leak of some kind? Bank 1 is the driver's side? Thanks for the info guys.

I wouldn't worry about the fuel trims -- they're not THAT far out, and not far enough to cause what you feel as a miss. Keep your eye on the short term trims and if they start moving to over 8 or 10% either way it will be time to look into them. You can reset the LTFT with your Tech 2 and start them from scratch if they bother you; they are what your STFTs have been doing over (past) time. You never know, maybe they're adjusting to the new muffler and the airflow. New breathing, maybe? Not sure how much different your new muffler is from the old.

 

[Tonyrodz]

I wouldn't worry about the fuel trims -- they're not THAT far out, and not far enough to cause what you feel as a miss. Keep your eye on the short term trims and if they start moving to over 8 or 10% either way it will be time to look into them. You can reset the LTFT with your Tech 2 and start them from scratch if they bother you; they are what your STFTs have been doing over (past) time. You never know, maybe they're adjusting to the new muffler and the airflow. New breathing, maybe? Not sure how much different your new muffler is from the old.

Both mufflers(old and new) are a straight through design, only difference with the new one is it's a little longer. To reset fuel trims, where would that be? Special functions maybe?

 

[Tonyrodz]

Checked the header bolts real quick and looked it over under the hood for any loose connections, or anything sucking air--nothing visible, everything feels tight. Fuel trims are still off between banks 1 and 2.

 

[97YukonNZ]

Checked the header bolts real quick and looked it over under the hood for any loose connections, or anything sucking air--nothing visible, everything feels tight. Fuel trims are still off between banks 1 and 2.

Have you thought about getting a plastic drink bottle of water and squirting a bit along the inlet manifold while shes running incase you have a vacuum leak?

 

[Tonyrodz]

Have you thought about getting a plastic drink bottle of water and squirting a bit along the inlet manifold while shes running incase you have a vacuum leak?

Haven't thought of that. Wouldn't carb or brake cleaner give the same results? If there is a leak what would the water do?

 

[97YukonNZ]

Haven't thought of that. Wouldn't carb or brake cleaner give the same results? If there is a leak what would the water do?

Yeah either of those will work. If their is a leak,i think when you spray either of them it will surge in idle letting you know where.
Water will stop the miss for a second and may show visully where a vac leak is present.
Was just thinking water because of it being free and available now!

 

[Fless]

How much has it been driven to see if the LTFTs line up better with the STFTs? Your short terms were perfect earlier in the week, and if they stay within +/- 5% they'll affect the LTFTs over time and those will get closer to zero. (Stop living in the past, LOL.) Look elsewhere for your miss.... carb cleaner, brake cleaner, propane, all can be used around the intake to investigate leaks.

 

[Tonyrodz]

How much has it been driven to see if the LTFTs line up better with the STFTs? Your short terms were perfect earlier in the week, and if they stay within +/- 5% they'll affect the LTFTs over time and those will get closer to zero. (Stop living in the past, LOL.) Look elsewhere for your miss.... carb cleaner, brake cleaner, propane, all can be used around the intake to investigate leaks.

I drove it a few blocks today. My gf drove it twice this week locally and she also noticed it wasn't running right. I can hear the exhaust note from the tailpipe sounds off--if that makes sense. At idle and while driving it.

 

[97YukonNZ]

02 sensors not disconnected or bad contact on 1 side of exhaust?