CEL caused by DC emission test

my 2001 Outback went through DC DMV vehicle test yesterday, and the check engine light was off when it went in and on when it came out - I'm assuming that it has something to do with the emissions testing? Anyone know whether it is likely to go off on its own, or is this going to be an expensive service trip? Thanks

Reply to
dfeary
Loading thread data ...

Best thing to do in case of any CEL is to pull the code. You can get it done at an auto parts store (i.e. Autozone) for free. Make sure you ask them for, and write down the code, because sometimes they will read it and tell you a generic meaning which can be misleading.

Once you have the code you'll know what the problem is... there are a few common ones that happen on most Subaru's eventually.

Reply to
Dmitriy

Mmmmm, you're not gonna like what I'm about to tell you, BUT . . .

My sister was in a depressingly familiar sounding fix recently; CEL immediately following a visit to a local service shop for a routine oil change on her '96 Legacy.

I borrowed an OBDC reader from a friend, and when plugged in, it spit out a "cam sensor" fault. Further investigation found that the plug on top of the cam sensor was loose (as in just sitting on the sensor, not "clicked" into place). Odd, because I was the last person to service the engine, and while it is entirely possible that I might not have gotten the connector all of the way on, it seems highly unlikely that the car would have traveled over 10K miles of bumps and ruts without it triggering a CEL if I had done so. Added to the fact that the cam sensor is readily accessible on the top of the engine, and you begin to see where I'm going with this. (Novel way to drum up service business, and an easy fix, too!)

FWIW, emissions testing involves putting a probe in the exhaust, a magnetic pickup near a plug wire, and running the engine up to a certain RPM while monitoring the exhaust gas, nothing more, and absolutely nothing that would cause a CEL to magically appear.

But then I have a nasty, suspicious mind . . .

Check any accessible electrical connections (Cam sensor, crank sensor, knock sensor, O2 sensor, TPS, temperature senders, etc) to be sure they are good, disconnect the battery for a couple minutes to clear the CEL, and see if that doesn't help. If the CEL persists, it is just possible that something failed simultaneously to the emissions test being performed. Possible, but unlikely :-P

ByeBye! S.

Steve Jernigan KG0MB Laboratory Manager Microelectronics Research University of Colorado (719) 262-3101

Reply to
S

Get a OBC reader, or have the code read, and then ask your favorite Subaru mechanic what the chances are that they can fix the problem. I had an evaporator emissions control fault that my mechanic said I would have to have the dealer diagnose with a smoke machine. Of course, once your car has failed the emissions test, then you have to get the thing fixed as quickly as possible during whatever grace period you're allowed. Or, did the car pass and the light came on afterwards? There should have been some failure report if the light had come on during the test.

Good luck,

Bill

Reply to
William Martin

In some states, they somtimes check other stuff visually, and MAYBE the gas cap was removed to inspect the size of the opening in the neck of the filler tube. If done with the engine running, it can trigger an Evap system code. Personally, I's probably look around a little, click the gas cap around a dozen times, disconnect the neg. battery term. ,step on the brake pedal, reconn, the batt. after 30 minutes or so, and see if the CEL comes back on fairly immediately. If not, just drive the car and forget it. If it it does return - get the code read.

I dunno

Carl

Reply to
Carl 1 Lucky Texan

Thanks to all who responded - - - the CEL magically disappeared exactly

24 hours after it came on !! I'm really still no wiser...

And to answer Bill's question - the vehicle passed the inspection, despite the CEL being on.

Reply to
dfeary

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.