Hi all,
I have a 1994 Jeep Grand Cherokee, 8 cylinder. I am having problems with passing emissions inspection in north NJ (Sussex County). The original results were:
Gas Standard Reading Result HC 100 27 Pass CO% 0.50 0.69 Fail CO2% 13.9 RPM 2668
No figures were given for NOx or O2%.
Okay, no big problem, thinks I. The following parts were replaced:
Oil filter & oil Air filter
8 Spark plugs Plug wires (including the distributor/coil wire) Oxygen SensorA mechanic checked the vehicle out, and had a friend of his test emissions. Despite the vehicle running excellently (no pings, knocks, stalls, bad starts, dirty exhaust etc.) they could only get the CO% down to about 0.51 - 0.52.
He tested a load of parts, and reported the following:
- Fuel pressure test - ok
- Coolant temp sensor - ok
- PCV - ok
- Air filter - new
- EGR - 100% working ok
- B-map - ok
- TPS - ok
- Injector Balance - ok
- Plugs, Wires - New
- Throttle body - cleaned, ok
- AIS Motor - ok
- Air control motor - ok
He couldn't figure out what the problem was, but suggested I simply put it through the test with a gallon of alcohol.
I filled up the gas tank with Mobil Super +, and drove around for a week to clean the fuel lines through. I filled up again with Mobil Super +, added a quart of dry gas and a gallon of denatured alcohol (so I'm guessing the tank would have had about 4% - 5% alcohol), drove it 15 miles and put it through inspection.
To my amazement, I got the following results:
Gas Standard Reading Result HC 100 30 Pass CO% 0.50 0.61 Fail CO2% 14.1 RPM 2430
I'm like .... WTF????
I've been told the local gas stations are putting additives in the gas in this area due to the weather, and a lot of cars are losing fuel consumption and failing emissions inspections. But this is ridiculous. I can hardly import a tank of gas from Florida, so what the hell else can I do to get this thing to pass?
Any suggestions gratefully received, short of "move to a state with less draconian measures".