Correct! Another good point.
I have found this to be a problem as well. More like a slight coating of dirt
not really carbon. (Looks like carbon build up on the film). I have found that removing and misting the MAF with alcohol will clean the deposits. I will dry it with a hair dryer set on low warm. A dirty MAF will falsely indicate less airflow causing the Computer to lean out the mixture.
A lean mixture will make the cats glow bright red and actually melt the Honeycomb inside. You really must be through when diagnosing a problem.
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-A