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Old 04-28-2020, 08:53 AM   #76 (permalink)
Tahoe_Hybrid
Master EcoModder
 
Join Date: May 2019
Location: California
Posts: 513

2020 - '08 Chevy Tahoe H
Last 3: 18.4 mpg (US)

2021 - '08 Chevy Tahoe H
90 day: 17.08 mpg (US)

2022 - '08 chevy Tahoe LT
Last 3: 14.38 mpg (US)

2023 - '08 Chevy Tahoe
Last 3: 22.61 mpg (US)

2024 - '08 Chevy Tahoe
90 day: 22.35 mpg (US)
Thanks: 2
Thanked 105 Times in 96 Posts
Quote:
Originally Posted by roosterk0031 View Post
My Cobalt fuel trim had been maxing out off and on for over a year before I finally figured it out. Evap Purge valve was creating a vacuum leak. My code was always a lean code, don't remember the number, even though it was running crazy rich. Got the first replacement part from O' store worked a few months. ACDelco part been working 5 months now.

Tahoe & Cobalt even have the same part number.
it's the MAF/IAT combo

the IAT is showing 20-30 degrees higher on a stone cold start.. the MAF might be incorrect as well as it back fired a few times as well

I run chevron fuel

the MAF/IAT sensors are a common failure

sometimes it cranks too long and goes to 1500-2000rpm(with it's obnoxiously HUGE Electrical 60,000 watt starter)

Last edited by Tahoe_Hybrid; 04-28-2020 at 08:59 AM..
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