Emission test FAIL

[Petersho1]

HC standards=0.80, I had 1.13
code on comp. 157, low voltage on MAF,
two weeks ago on dayno engin runs lean, AFR=15,5

As I understand lean = not enough fuel or too much O2
HC=unburnt fuel in exhaust, so engin is not getting enough fuel and that rest of is not burn. Look like I'm wasting money for gas, all what my car needs is just air.

 

[AutoSHO]

Are you running a K&N air filter?

Running lean means the car is not getting enough fuel to match the amount of incoming air, like you said. High HCs are typically a sign of unburnt fuel (misfire) or a rich condition.

Chances are cleaning your MAF sensor of the filter oil from the K&N will solve your problem of running lean on the dyno. It may also fix your mixture problems at part throttle.

When did you last replace your Oxygen Sensors? ECT? Plugs and Wires?

 

[Petersho1]

Yes K&N filter, new O2 sensors, new wires, plugs looks good, Oh!, maf was cleaned three tims last 3 weeks, and tryed second one 75mm still getting 157 on both.

 

[Stracey R]

How are your catalytics?

 

[AutoSHO]

What kind of fuel economy are you getting?

 

[Petersho1]

20-23mpg

 

[Blue-By-U]

HC too high, huh? Mine also failed that portion. How old are you plugs and wires? After I changed mine my HC numbers went down.

Edit...sorry I didn't realize your plugs and wires were already new.

 

[Petersho1]

wires are new, plugs 20K miles,looks gray.

 

[AutoSHO]

20-23mpg

On the highway? Around town?

Have you checked fuel pressure? Does the cooling fan come on when it is supposed to?

 

[Petersho1]

pressure 40psi, cooling fan ok, just checking KOER........111=pass!!! Don't see any vac. leaks.

20-23 50% highway,but love when secondary opens , lots of 2 miles trip on cold engine, so it's not so bad.