ONLYA4.8L

My SES light turned on in my truck on friday.. I got the codes read.. Hopefully this will explain why my truck has been running like ***...
1.MAF low input
2.Knock sensor 2 cicuit low
3.Evap emmissions control purge valve C/Faulty
4.Evap control system vent valve/solenoid malfunction

So any ideas?

budhayes3

iTrader: (19)

Whew, four codes...wtf? Is it possible that some are old history codes? I guess the best thing to do is look for something common to all of those circuits first, then tackle them one by one. The Maf code may be related to the maf being ported, or possibly coated in air filter oil if you have a reuseable air filter. Knock code may be corrosion/moisture on the connector to the knock sensor, faulty wiring or knock sensor. EVAP codes could be related to a loose gas cap, or even topping off the gas too much...believe it or not. (I've seen charcoal cannisters get flooded from this, and purge valves get saturated and purge raw fuel instead of just vapors, as they are designed to do)...could have some other leak in the evap system, or a bad solenoid, cannister, etc.

One of the recent vehicle's that I personally saw with that many codes in different circuits had just been detailed and the engine was either shampooed or steam cleaned, and moisture worked it's way past many of the "sealed" connectors.

mason110

wow all this in one shot? sounds kinds strange to me!! possibly old codes

ONLYA4.8L

All new codes.. Ill try replacing the knock sensor and MAF and see what happeneds.. Will the MAF and knock sensor make it run a little over a second slower? I went to the track on friday and I ran a 15.78 at 85... I usually run mid to high 14's.. My best 14.55@93mph... on avg 14.6-14.9... So wtf?

budhayes3

iTrader: (19)

I would think that maf and knock issues would have a direct effect on performance, whether it be due to the PCM getting incorrect info, or by going into a failsafe mode with fixed values to allow operation.

ONLYA4.8L

Well thanks for the info.. If you guys figur out anything else let me know...

ONLYA4.8L

Replaced my MAF and Knock Sensor but codes still remain:
P0102
MAF or VAF
Circuit low input
P0443
EVAP Emissions
Control System
Purge Valve C Fault
P0449
EVAP Emissions
Control System
Vent Valve/Solenoid Malfunction
And It still drags ***.. DAMMIT!!! Any ideas