Title says it, 96 Outback wagon, 4EAT, 340K miles, took it to get smogged today and it failed at idle, with 158PPM (max is 100PPM). It has been so long since I have had any issues with smogging a car that I have forgotten how to bring down the HC number. Any clues?

 

Our '96 Legacy wagon failed at idle too (they had the gall to call it a "gross polluter" ). It was a single bad O2 sensor. I didn't replace it myself, so I don't know exactly what was involved, but it wasn't expensive. It passed with flying colors after that. BTW, our's is a young pup -- only 240k miles.

Edited February 27, 201313 yr by bendecker

Had any decrease In fuel economy lately?

When was the last time it got some simple things like plugs wires and filters?

Run some fuel system cleaner in case the injectors are dirty. O2 sensor is a good possibility if it hasn't been changed in the last 100k miles.

The O2 sensors are both less than 50K miles old, genuine Subaru, both replaced at the same time, while I had the engine out to replace the T-belt and seals. Replaced the plugs at the same time, as well as the air filter. I have been getting P0420's since before I replaced the O2's and the PO was fond of using really cheap gas (also skimped on maintainance as well, but that is another thread. . .) I am suspecting that it is the cat, but I am really hoping not. I have not yet run seafoam through the top end, and may do that today. I was just hoping for another answer. . . *sigh*

if you don't want to fix the problem (time, money or both). i know of a way to get you to pass for HC's... You can PM me if interested.. Not really ethical but it usually does the trick I don't want to post it out in the open either.

There is an auto store item called guaranteed to pass or something like that for emissions testing.

Check your local stores.

 

O.