280+k 90 Legacy

Passed!!!!Passed!!!!Passed!!!!Passed!!!!Passed!!!! Ok here on the numbers: RPM: 691 %CO2: 13.8 %O2: 1.7 HC (PPM) Max: 120 AVE: 29 Meas: 35 CO (%) MAX: 1.00 AVE: 0.10 Meas: 0.00 RPM: 2662 %CO2: 14.6 %O2: 0.5 HC (PPM) MAX: 140 AVE: 20 Meas: 22 CO(%) MAX: 1.00 AVE: 0.10 Meas: 0.00 Passed!!!!Passed!!!!Passed!!!!Passed!!!!Passed!!!! Hopefully I'll get another 300k out of the car

Thanks for the help everyone. I tried E85 fuel and it took 100 PPM off the HC. This was still not good enough to pass. Today I took the car to an exhaust place. It turned out the front cat was fine and original. The back cat had been replaced and had nothing left but a ball of wire mesh. Replaced the back cat for $200 and the car passed smog with flying colors. I'll post the final number shortly. Thanks again for all the suggestions. Maybe this thread will be useful to someone else.

Hi Everyone, Thanks for your replies. The car is an automatic, 1990 Subaru Legacy with the 2.2L engine. It has 288,000 miles on it and runs great. I get around 25 MPG on a tank or about 300 miles to a tank of gas. No check engine light or codes in the ECU and no rotten egg smell. I pulled the spark plugs and checked the gap this weekend and everything looked ok there. I also put in a can of 'Guaranteed to pass' (a engine/fuel system cleaner) in the fuel. I've been running 91 octane fuel in the car for as long as I can remember. From what I've been reading, HC is caused by unburnt fuel and high octane fuel burns slower than lower octane fuels. So I was thinking after I finish this tank of gas with the 'Guaranteed to pass' stuff putting a few gallons of 87 in it seeing how it runs and if everything checks out trying the test again. As for the E85 I've read about people doing that. Does it really work? Thanks for the help!

I took my car in to get it Smogged today and it didn't pass. The HC was over the limit at idle but everything else passed. Here's the numbers Idle RPM 691 %CO2 13.6 %O2 1.2 HP (PPM) Max 120 GP 270 Measured 324 CO (%) Max 1.00 GP 2.50 Measured 0.70 Not Idle RPM 2560 %CO2 14.0 %O2 0.6 HP (PPM) Max 140 GP 290 Measured 49 CO (%) Max 1.00 GP 2.50 Measured 0.66 I did a major tune-up earlier this year when the car was not running well. I think I remember buying cheap spark plugs and I'm thinking maybe about getting the NG plugs. Not sure this would solve my problem though. From what I've been reading high HC levels mean there is unburnt fuel. I'm currently running 91 octane full. Maybe I should put an additive in there before my test? Thanks for the help.

FIXED!!!!! Got another MAS from the junk yard, cleaned it, put it in and the car has ran great for the past two weeks. As for gas milage I've been getting around 26 MPG! :banana: :banana:

I cleaned the MAS I got from the junk yard, installed it, and took the car for another ride. It started up cold and ran great...for about half an hour and then the car just died. I tired to restart it but it was running really bad. The car sounded like it was running on 3 cylinders and smelled like it was running rich. There was no power and I could not drive, so I put the odd MAS back in and drove home. I think my MAS is going bad and the one that I picked up from the junk yard is good for a short time and then goes out. This is the second time I've tried the MAS from the junk yard and it has preformed exactly the same both times. I'm still going to try the other items on my list, but so far, I think the problem is most likely my MAS.

I took back the MAS that didn't fit my car today and the ECU that didn't help. I pulled another MAS from the car in the yard that was the same year. This time I made sure that the model numbers were the same. I put it in and the car ran great for half an hour! The idle was steady and the pickup was clean when I accelerated. Just when I started to gain confidence that this was going to fix my problem the car stalled out when I was approaching a stoplight. When I restarted it and it was running really erratically. It would almost die and then recover and then do it all over again. Luckily I still had the other MAS and was able to quickly swap the new one out for the old one and drive home. So I'm thinking that maybe my MAS is going bad and that maybe the one that I got from the yard is either bad as well or needs a good cleaning. So here's my weekend laundry list: Clean the new MAS Check the wiring to the 02 sensor Compression test the engine and check the spark plugs Check the fuel pressure I'm really hoping cleaning the new (used) MAS will fix my problems. The car ran so well for that half an hour!

Thanks Mark. I replaced the spark plug a week or two before I found the problem with the wire. When I do the compression test I'll be sure to check them as well.

So the O2 sensor is not used when the car is warming up? The stumble on the highway was fixed with new spark plug wires. Once the car is warm it seems to be ok for the most part. Some times it feels like its lacking in power. The only code I get is a 32 for the 02 sensor. I don't think these older cars with OBDI will give codes for a miss fire. Also my gas mileage is about 2/3 of what it was before this problem.

Thanks for the help everyone. Looks like I'll be spending some more time under the hood this weekend. I'm hoping it's just a wiring problem. I'll keep you all posted as to what I find. How hard is it to do a valve job? Also if it was a valve problem wouldn't the car run bad all the time?

Keep going!!! My 90 Legacy with the 2.2 is currently at 284k. I love this car. I haven't had many problems with it at all. Oil change every 3k, cv joints and tires. Currently working on fixing some new problems but I'm hoping to get a few more years out of the car.

Thanks heartless. I've read in other places the same thing but was hoping to save a few bucks and the parts store near me didn't stock the bosch replacement with the plug on it. I went for a drive after work today and picked up the OEM one from bosch with the plug. Put it in, cleared the old code and took the car for a drive. I didn't get half a mile before the check engine light came on. Checked the code an it was once again the oxygen sensor. At this point I'm thinking maybe it's a wiring problem. I'm not sure what the best way to find where it is though. Any other ideas what it might be? Thanks again for all the advice!!!

Thanks Olnick. Looks like I can get these delivered for around $40. I called the dealer and they want $50 for the OEM ones. Not sure which one to go with. I can get the dealer one tomorrow or save $10. Also the dealer one might fit a little better?

Uploaded a new video of the car starting cold. This time with the new spark plug wires and the replaced ECU. A little better but still not right. It's still stalling out. The check engine light did come on and the code was for the 02 sensor. I think this was the first time I've seen the the 02 code when I start the car cold. Most of the time it just comes up on the freeway. Here's the link:

Here's some photo's of the old, factory?, spark plug wires: The hole: