Emissions failure on HC... sugestions?

[einreb]

Well...

My 88 with a euro cat and chip (set the dme switch to position 3 )failed the HC test...

readings of 3.19 gpm, 0.80 is required. What does this tell me?

The CO was 11.4 with a pass requirement of 15, so I was OK there.

I have the old cat, but the o2 sensor is fused in it... would it help to put it back on? (what does the cat cut down on?)

Plugs have about 8k on them and look ok... will likely replace them anyway.

I'm also considering the JW disconnect the injector wire suggestion... thats a good one

Any other thoughts/suggestions? thanks!

-bernie

[john walker's workshop]

washington does parts per million, ppm, so i can't relate to gpm. unplug one of the electric injectors and redo the test. #4 is easy to get to. it's like adding an air pump. best to figure out the real problem soon as possible, but if you're in a pinch, this usually gets it thru if it's just a bit high.

[MotoSook]

"I have the old cat, but the o2 sensor is fused in it... would it help to put it back on? (what does the cat cut down on?)"

You have an O2 sensor on the euro pre-muffler right? I didn't think a DME car would run very well w/o the O2 sensor..but then what do I know...I don't like fat pigs

[einreb]

Originally posted by john walker's workshop
washington does parts per million, ppm

gmp is Grams Per Mile (I think). won't cutting out one cylinder just reduce the emissions by 1/6th?

what problems (bad things that would hurt the engine) cause this high number?

would reinstalling the cat help at all? Im under the impression that it will turn the HC into carbon dioxide and water... but dont know if i'm right. my concern with the cat is that its old... when i replaced it with the euro cat i couldnt get the old o2 sensor out, so if i put it back in... its going in with the old sensor. could be a whole nother set of problems.

[midlife]

High HC could be caused from a bad spark plug wire.

[john walker's workshop]

plug wire, plug, air leak, valve leak, leaking injector, too rich, too lean, the list goes on. anything that sends unburned fuel into the exhaust.

[einreb]

Well... it passed. What a great way to spend the day. Not sure what the fix was. I ended up...

Reinstalled the old Cat
New plugs (old ones looked ok)
Ran the ***** out of it to get it hot and bothered prior to the test (per the suggestion of the toothless '68 VW owning emissions tester).

But... I suspect that the culprit might have been a loose plug wire

Interesting to note... it definately lacked a certain umphf with the cat back on.

Thanks to those that responded... especially JW... this is the second time you've posted when I've been in greased up typing panic attack mode.

[Joe Bob]

Fix the obvious...cat and 02, then sweat the little stuff.