High NO and HC on smog 94 e320
Thread Starter
Senior Member
Joined: Jul 2004
Posts: 462
Likes: 3
From: Boulder, CO
86 W124
High NO and HC on smog 94 e320
Hey everyone,
I've got a few questions about the m104 hfm, please chime in.
Story goes...
3 failed smogs...
first run(middle), not warm but also not cold catalytic converter.
second run(top), Cold cat, egr unclogged.
third(bottom), 3500 rpm for minutes so hot cat and tested right away, new O2 sensor.
Since last year, when it borderline passed, the only difference is a fan clutch. The engine is always 80C, as opposed to getting to 100C.
Somewhere in there a can of sea foam passed through the intake.
MAS sensor cleaned.
Cylinder compression is the same (175), plugs changed a year ago with copper, all read okay, even but on the rich side. Checked for spark, all strong. A bit of oil from the valve cover gasket; drops and not soaking to the top.
Harness good; runs like a champ, idles smooth, and start anxiously on the first crank.
Why is it rich? What tells it to dump fuel? The ecu temp sensor(new 1 year ago)?
Air filter is new. It received a lot of maintenance parts over the past year but smog is still the same. Cat seems good. Everything is pointing to running very rich at idle...
Thanks for the input!
I've got a few questions about the m104 hfm, please chime in.
Story goes...
3 failed smogs...
first run(middle), not warm but also not cold catalytic converter.
second run(top), Cold cat, egr unclogged.
third(bottom), 3500 rpm for minutes so hot cat and tested right away, new O2 sensor.
Since last year, when it borderline passed, the only difference is a fan clutch. The engine is always 80C, as opposed to getting to 100C.
Somewhere in there a can of sea foam passed through the intake.
MAS sensor cleaned.
Cylinder compression is the same (175), plugs changed a year ago with copper, all read okay, even but on the rich side. Checked for spark, all strong. A bit of oil from the valve cover gasket; drops and not soaking to the top.
Harness good; runs like a champ, idles smooth, and start anxiously on the first crank.
Why is it rich? What tells it to dump fuel? The ecu temp sensor(new 1 year ago)?
Air filter is new. It received a lot of maintenance parts over the past year but smog is still the same. Cat seems good. Everything is pointing to running very rich at idle...
Thanks for the input!
Last edited by ptoro01; Jan 3, 2013 at 02:34 AM.
Junior Member
Joined: Jun 2006
Posts: 38
Likes: 0
From: Laguna Niguel, CA
95 E320 Cab (new toy), 06 Range Rover (Hers), 97 Ferrari F355, 05 Ariel Atom 2 (the other toy)
My 95 E320 failed smog with HCs at 148. I used CRC Guaranteed to Pass for $11.99 and it passed with the HCs down to 11!
For $12 and a guarantee to refund double your money, it maybe worth a shot.
I posted this on another post with a pic.
HTH
Omar
https://mbworld.org/forums/attachmen...smog-image.jpg
For $12 and a guarantee to refund double your money, it maybe worth a shot.
I posted this on another post with a pic.
HTH
Omar
https://mbworld.org/forums/attachmen...smog-image.jpg
