dtran002

I did mine last week and failed the 15 MPH test. The result were:

HC: Max: Meas: CO: Max: Meas: NO: Max: Meas:
15 mph 88 166 0.52 0.6 704 874
25 mph 53 53 0.5 0.06 738 407

My mechanic think it just a bad cat, should I worry about the O2 sensor as well or just change to a new cat and have it retest?

Rob97'SH

What year is your lude? If its obd2 it (should?) triger the engine light on if it were the cat. How far off were your readings?
Just need more info at the moment.

viper-blue

Honestly with your numbers, I would try a tune up and retest first. A brand new cat might make you pass a retest, just because it is new and better than the one you have on your car. The problem is that the cat just eliminates what the emissions system on the engine cannot get.

For a mechanic to suggest that as a first option tells me he might be lazy, considering you barely failed.

I had quadrouple the limit on HC and NOX, and triple the limit on CO. Everyone I talked to said change the cat and be done with it. I ended up cleaning the EGR, put in the proper heat range of spark plug, and adjusted my timing as it was advanced 2 degrees from stock specs.

Just doing those three things made my car blow zero practically. I've since found out my cat is just a test pipe so trust me you don't have to waste your money on a cat, there is a cheaper alternative and its likely timing, or 02 sensor related since your running a little rich at idle. A new cat might cover up the problem, but the problem will still be there. The high nox could be as simple as running a plug that's too hot for your engine or mild overheating. Get a second opinion for sure.

Inextricabledrvr

I would get a tuneup...ie spark plugs, wires, cap, rotor etc. Another thing should do is make sure your cat is hot when you get to the smog station. So, that means you should hit VTEC a few times before you get there. Good luck man. CA emissions is a major PITA!

DCFIVER

looks like you got a small fuel leak.

dtran002

hey guys, thanks for the inputs. I already done spark plugs, cap and rotor change a week ago. The timing is at 15 BTDC, so I should advance it to 17?
As far as the wire, it is still the same one, roughly 13k on it. I haven't clean the EGR yet nor know how to do it. That's what my dad also said, have that thing clean out and try again too.
I will try to clean out the EGR valve tomorrow, hopefully that will lower down the NOx. What about the Hydrocarbon and CO? What I should clean/change to reduce the output amount of those two?

viper-blue

You might as well try a long drive, then go to a drive-through emissions testing facility. You've taken care of the tune up items already, and only failed on the 15mph. Just get everything super hot and retest.

Don't advance the timing though because that will just make your nox and CO levels higher.

dtran002

Thanks viper, I'll have it recheck this sat and see what the result will be.

dtran002

Thanks for all your tips guys, I cleaned out the EGR, retarded the timing and drove likes 40 miles before retest. It passed.