I had this trouble every time with my ¡¯84 Vanagon. I could get it to pass with a high idle (just under the 1100 max they allow here). It didn¡¯t have a cat, but was supposed to. Richen it up a tad, and crank up the idle, and try again before throwing money at it. Better yet, have a shop that guarantees passing tweak it. We have a guy here that has a van with a Sun tester in it right next to the emissions test station. For $40 he would even take my Vanagon through for me. It passed every time! (I think he bribed the testers!)
Stuart
¡¯97 EVC, Seattle
_____
From: ev_update@... [mailto:ev_update@...] On Behalf Of Ian Mothersill
Sent: Wednesday, June 18, 2008 2:01 PM
To: ev_update@...
Subject: [ev_update] Failed Smog Test (Aircare) but closer this time....
Hello all,
The short version is, what do you check if the NOx is too high (and CO
is close to being too high) to pass the smog test?
A while back I failed the Vancouver-area "Aircare" smog test with very
high CO and HC readings (posting #103838). Turned out the blue 2
wire temp. sensor wasn't plugged in properly, so I was running in
default rich mode. This happened when I was diagnosing "no starting"
problems. I burned about ?? tank of gas with the sensor unplugged.
Plugged it back in, and the van ran better and didn't smell of gas.
So I waited for a couple of tanks of gas, some around town and some
highway driving, then went back to re-test. I also installed a 470
ohm resistor in the circuit to the Intake Air Temp sensor; haven?€?t had
any instances of high idling since then (something that happened from
time to time before). This time, HC and CO are OK, but NOx is higher
- high enough to fail.
Plugs, Cap, rotor, and wires are all new.
The readings on the first test were:
|max Allowed | reading | Avg. Pass
HC | .9900 | 1.6849 | .3049 >> FAIL
CO | 12.43 | 36.8187 | 6.1019 >> FAIL
NOx | 1.5500 | 1.2423 | 0.7272 >> Pass, but higher than
average
The readings on the second test are:
|max Allowed | reading | Avg. Pass
HC | .9900 | 0.6051 | .3049 >> Pass, but higher than
average
CO | 12.43 | 11.1820 | 6.1019 >> Pass ?€" barely!!
NOx | 1.5500 | 1.7398 | 0.7272 >> FAIL
I seem to remember that high NOx is often a catalytic converter gone
bad. Is that the case? Anything else to check out, such as the
Oxygen sensor? Timing?
My van has a ?€?generic?€? converter that was put in a couple years ago by
a previous owner. The front pipe that comes with the ?€?factory?€?
converter is wearing through, so if it is the Cat I can kill 2 birds
with one stone on this.
Thanks.
Ian Mothersill
93 EV Weekender 5 speed
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