my 1986 245 is a GROSS POLLUTER

Blubrick · Post by **Blubrick** » 04 May 2011, 14:28

Sheesh. I love this car. I want to drive it forever...
Got bad news at smog check today, "Gross Polluter" news. My instinct tells me to have the cat changed out.
I'm also going to replace plugs, plug wires, run some fuel injector cleaner through the gas, and perhaps replace the air sensor.

Here are my stats:
15 mph 1639rpm 13.5% CO2 .8%O2 HC-110(133 max) CO-.53%(.82% max) NO-2446ppm(1125 max)
25mph 2560rpm 14%CO2 .2%O2 HC-53(108 max) CO-.37%(.62% max) NO-1967ppm(955 max)

What does it all mean????

Any advice is surely appreciated!!!

Post by **VCA** » 04 May 2011, 15:26

High NOX with normal readings otherwise is likely indicative of a lean mixture--vacuum leaks, bad AMM, bad O2 sensor. Is the check engine light on?

Blubrick · Post by **Blubrick** » 04 May 2011, 16:41

No check engine light, but my instrument panel has been acting up (old, crusty wiring!). I looked it over carefully and see no visible leaks. Will check the O2 sensor.

AMM?

ed7 · Post by **ed7** » 04 May 2011, 17:35

You're stuck with the biodegradable wiring.
.2% o2 is lean, .8% o2 is rich
High Nox is from high combustion temps, check EGR for inop condition /lean mixture.
o2 sensor should read about .45 mv optimum
Vacuum leaks are common on these intakes, check air filter and that thermo-flap in air cleaner is disabled toward the cold side.
Bad AMM can lean the mixture also.
Check plugs and timing.
Ed

Post by **billofdurham** » 05 May 2011, 11:50

AMM?

Air Mass Meter otherwise known as Mass AirFlow (MAF) meter.

Bill.

rob444-960 · Post by **rob444-960** » 27 Sep 2011, 13:11

Hello Blubrick,
I am also in S.F. BAY AREA and have a 740GL that passes smog except for NOX [Gross polluter numbers like yours]. I keep getting 232,231 codes. Were you able to cure your NOX problems and pass smog? I would appreciate you sharing your magic as I have spent way too much time and money trying to register this car for my daughter. Thanks, Rob