Hello everyone,

I have a 1987 240DL with 100,000 miles on it that I'm trying to get licensed and was nearly stunned with my emissions results.

HC Hydrocarbons = 22.6 (allowed 0.8)
CO Carbon Monoxide = 220.6 (allowed 15.0)
NOx Oxides of Nitrogen = 0.4 (allowed 2.0)

C02 Carbon Dioxide = 241.8 Grams/Mile


Prior to the emissions test I had changed the oil, installed new plugs, wires, cap, rotor, cleaned and reconnected (was disconnected) the flame trap.

I took the test warm with premium fuel and STP Fuel Injector Cleaner in the tank.

The fuel filter looks as if it's never been changed. Couldn't break the bolts loose, PB Blasted 'em and will get it later today.

The catalytic converter appears to be old but does not produce the standard oders or pinging noises of a bad converter.

In addition, the vehicle also has a random stalling issue. It can stall at any time, within a short trip, or later in a longer journey. It can stall repeatedly in a short period of time, or it can run seemingly well for extended periods without stalling at all. It seems to stall most often when either accelerating from a dead stop, or when removing your foot from the pedal to decelerate. It well just shut down as if not getting fuel, or not getting spark.

When it stalls it doesn't usually start up right away. The engine will crank, but again it seems as though it's not getting fuel and/or spark. After some time, say 5 to 30 minutes, the car starts seemly normal and runs seemingly well until it dies again.

While I'm somewhat mechanically inclined I am not a mechanic. I do have a mechanic who's helping me solve the problems.

My question is what could be the likelihood that these issues are related, and where would you recommend looking next?

Thanks in advance.