Emissions Testing re. Used Car Purchase.

[George7941]

This morning I checked out a 1999 VW Jetta with a 2.0L engine that a friend of mine was considering buying.

The car passed Safety Certification and Emissions Testing yesterday. I am in Toronto, Canada.

When I plugged my scanner in, three misfire codes came up, Engine Misfire/ Cylinder 1 misfire/ Cylinder 3 misfire. I think the numbers were P0300/P0301/P0303.
I am using a Innova 3130 scanner. My question is -- can cars pass emissions tests with fault codes present?
I also checked cranking compression in cyl 1 and it was 205psi.A relative compression test with a amp clamp around the starter cable showed equal compression on all cylinders.

What might be likely causes of this misfire? Should I recommend against the purchase because of this misfire?

The two plugs I removed(#1 and 4) looked normal.

 

[willix]

It passed.

 

[George7941]

Yeah, it did pass. I was under the impression that presence of emissions fault codes would preclude passing of the emissions test.

The owner of the car actually showed us the test results,indicating PASS. I did not get a chance to read it.

 

[willix]

2 out of 4 cylinders miss firing would at the least make the car run really horrible. If you bought the car it must not have ran that bad. I would guess an intermittant problem such as a plug wire acting up on a rainey/humid day may be the culprit.

 

[George7941]

Engine runs fine and you cannot feel any misfire. My friend hasn't bought the car yet. I am hoping to get some info here as to whether we should go ahead with the purchase. The price is $2000.

 

[Scienceman]

IMHO that almost seems to cheap. I may be wrong though.


Wonder if there is something going on???

 

[The_Jeff]

A misfire fault precludes most/all of the I/M readiness monitors. Did you happen to scan those as well? Generally you need most of those completed as well to pass a govt emissions test.

I'd skip it. If they bribed their way through emissions, we don't know it but maybe, they could have overlooked some safety issues too.

Was this car at a dealer? What's the inspection rule there, on transfer only or at some interval?

 

[xxch4osxx]

Originally Posted By: eljefino
A misfire fault precludes most/all of the I/M readiness monitors. Did you happen to scan those as well? Generally you need most of those completed as well to pass a govt emissions test.

I'd skip it. If they bribed their way through emissions, we don't know it but maybe, they could have overlooked some safety issues too.

Was this car at a dealer? What's the inspection rule there, on transfer only or at some interval?
They will run the emissions test even with the check engine light on here. The only thing they check is if the gas cap is on tightly, they don't hook the computer up at all. If it passes with the check engine light on, then all the better for you. The only way they will fail is wether the emissions from the tailpipe exceed the limits set.

 

[sciphi]

If I were mechanically inclined and had an extra $700 or so for parts, I'd hit it.

If it passed the tailpipe sniffer with a misfire, so much the better!

 

[George7941]

Originally Posted By: eljefino
A misfire fault precludes most/all of the I/M readiness monitors. Did you happen to scan those as well? Generally you need most of those completed as well to pass a govt emissions test.

I'd skip it. If they bribed their way through emissions, we don't know it but maybe, they could have overlooked some safety issues too.

Was this car at a dealer? What's the inspection rule there, on transfer only or at some interval?



None of the I/M icons were flashing, they were all solid indicating all the monitors passed.

When a vehicle is hooked up for testing, the Ministry of Transportation's computer at their office can communicate with the vehicle computer, so it is not easy to fake test results.

Private sale, no dealer involved. Seller seems very honest. Testing required every two years and at time of sale.

Probable explanation seems to be what xxcho4sxx posted, they only look at the emissions from the tailpipe and do not care if DTCs are present.

 

[sciphi]

I half-wish they did that in NY. A lot of cars would pass despite having a CEL on. They don't care if your car is running poorly as long as it doesn't set a CEL.

 

[mechtech2]

In Illinois, no codes can be present .
Any codes or a non working OBD2 system, and you fail.

 

[willix]

If the car looks good other than that maybe get it tested again. Surely you have confronted the issue with the seller. It could be leverage for haggling.

 

[JustinH]

Originally Posted By: mechtech2
In Illinois, no codes can be present .
Any codes or a non working OBD2 system, and you fail.


Same system for NY.

But of course, the worst offenders are cars made pre 96, so someone can drive around with their 79 hoopty blowing smoke down the interstate.

 

[NYSteve]

Downstate they will do a sniffer on pre-96