A Dodge Neon and a Volkswagen ???

1995 Dodge Neon No Power and a Volkswagen with high NOx Emissions

Dec 14, 2006

A 1995 Dodge Neon that doesn't want to go past 40 mph and a 1997 Volkswagen ??? with high NOx emissions.

Question: Dodge Neon Losing Power

Hello there. I have a 1995 Dodge Neon 4 door 212,000 miles with a fuel injected 2.0 liter engine.

My car has been acting weird for 2 months now. I have changed the fuel pump and fuel filter and I have a new gas tank. After driving for 10 minutes, it seems like my car just doesn't want to go past 40 mph. I have also noticed that my gas mileage has gone down and it has been eating oil and transmission fluid, not like crazy but needs to be topped up every 1 or 2 weeks. I was just wondering what I should check.

Answer:

There was a TSB, number 18-18-94 issued Sep. 9, 1994 by Chrysler concerning 1995 Dodge Neon models with a condition very much like yours. This bulletin involves replacing the Powertrain Control Module (PCM), and on manual transaxle equipped vehicles built prior to January 28, 1994, replacing the Crankshaft Position Sensor.

I would have your Dodge Dealer check it and confirm this TSB does indeed apply to your vehicle.

I think with 212,000 miles it's entitled to use some oil and ATF, although I would recommend the consumption be checked be a technician to see what shape the engine and transmission are in, just to be on the safe side.

Question: Volkswagen High NOx Emissions

Mr. Ciulla, I am working on a 1997 Volkswagen with high NOx readings, all other readings are great. Will not pass California smog. That's caused by hot combustion I think, correct? Go to a cold plug or make richer? Any ideas?

Answer:

You are correct in that high Oxides of Nitrogen (NOx) emissions are caused by high combustion chamber temperatures. But changing spark plug types will not lower combustion temperatures.

It is the function of the Exhaust Gas Recirculation (EGR) valve to lower combustion chamber temperatures and lower NOx Emissions. So high NOx would indicate a problem with the EGR system. Since you saw fit not to tell me what model and engine you're working on I can only give you general items to check.

One possibility is the EGR valve or the EGR passages are clogged. With the engine running disconnect the vacuum line to the EGR valve. Slowly apply vacuum to the EGR with a hand held vacuum pump. As you apply the vacuum the engine should start to run rougher and eventually die. If it does the EGR valve and passages are okay.

So that leaves the EGR controls. These vary by engine so you will need to use a manual and scan tool to diagnose the EGR system on your vehicle.

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