Smog Test High - How to Test Solution?

SMB123 · 09-02-2018, 05:11 PM

Hi, my 1994 Ford with 351W tested very close to limits in smog (but passed). Other vehicles I've had in the past were well within tolerances.

The smog place said it could be an oxygen sensor.

I would like to fix this before I sell (in the future) since that's a potential nightmare in California.

Is there any way to actual check emissions other than going to a smog place? For those of you who have had this issue - what resolved it?

The van runs like a top so I have no complaints otherwise. This is a conflict of "if it ain't broke" and morbid curiosity, I guess.

Thanks.

carringb · 09-02-2018, 08:31 PM

Road trip up to Oregon. Voluntary smog checks are free at DEQ stations. They are all over Portland but also in Medford. Besides, sometimes a good trip is really what it needs anyways to clean things out.

MountainBikeRoamer · 09-02-2018, 10:04 PM

You got me intrigued with this too -- so I did a little reading.

What I found:
In CA, you can go to a State-certified smog test facility and request what is called a "pre-test" --- this is a full smog test, and its results will indeed get recorded, but those results **won't count** towards your smog certification. So it doesn't cause you any grief with penalties.

But --- it does have to be done **before** your bi-annual smog check has come up for renewal. So the takeaway seems to be....probably the best thing to get that van's potential smog issues figured out well before you're up against the smog renewal deadline.

Can I Get a Smog Check Before it is Required by the DMV?
https://m.smogtips.com/OnlineForumQu...red-by-the-DMV

TomsBeast · 09-03-2018, 08:50 AM

First you need to know where it's close to the limits, armed with a copy of your old test results will help immensely: Hydro carbons and NoX are the typical.

I'm an amateur for sure, but have spent a fair amount of time researching and tuning (2) failing cars back into local compliance (86 Samurai and 2000 MR2), and I'm in the SF Bay area, which has one of if not the most stringent set of emissions requirements.

Most shops that do emissions repairs will have an older machine handy, that's not connected to Sacramento, that helps them diagnose. A sharp technician can look up the limits for your rig, check the output on the older machine, then offer up an educated guess as to what is usually the culprep "on these old Ford 351's"...