High carbons on emmision testing
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High carbons on emmision testing
Keep getting high carbon emission's readout for my 1987 f-150 4.9 6 cyl. efi. Cleaned sensor terminals on MAPS, PIP, & THROTTLE POSITION SENSOR. Does need a tune up as seller informed me he had tuned vehicle but he had not. Will tune up with Motor Craft parts. Pulled # 1 plug and it looks clean like its been burning lean. Should I take a look at replacing EGR sensor. Truck has 93,000 original mile's. Don't want to jump right to Cat's yet as I don't like throwing money at things but rather the challenge of isolating the inoperative part. Also heard EGR tube flow can be partially blocked with crumpled up tin foil to restrict NOX flow to EGR and this fools the PCM to adjust feed to injectors. Engine character wants to run lean. Is this correct? 
Last edited by rustywrench; Oct 21, 2013 at 10:51 PM.
