My question is what would cause high HC and CO in emmision readings? The only thing I noticed lately is increased knocking during acceleration, would that have any effect? I did the usual before the testing (filter, oil, plugs, timing) but stil failed. Also, I noticed the coolant is overflowing at times from the plastic reservioir when the engine gets hot. When cold, the coolant drops almost below the min. level. Another strange thing is , that idle does'n drop as usual and stays above 1000 rpm (didn't hapen before). Is there something seriously wrong with the engine? Shold I be looking at rebuilding the engine (it has only 160 000km - 100 000 miles on it. Also, could anyone reccomend some decent and reliable shop or a guy in Vancouver (BC) area that is familiar with Subarus? Iwould really hate to get rid of this car, it has done very good to me so far, so any help voul be appreciated. Thanks.

Is your 'Check engine' light on?

 

Have you gotten any error codes from the computer?

 

Here's a link to reading soob codes.

 

Soob Error Codes

 

Also, a corroded, dirty FI Coolant Temp Sensor can play hell on your fuel mixture, in turn playing hell on emissions

I had previously problem with the EGR Solenoid Valve, which I replaced (after driving with it for about a month) and the code cleared up. Is ir possible that the EGR valve got damaged and is causing the series of problems? Any ideas,suggestions? Thanks.

Doubt it got damaged.. might need to be cleaned out though.

 

Still If I were to pin your problems on one area, that FI coolant temp sensor is where I would start.

 

You state that you are getting knocking on acceleration.. what sort of knocking? we talking pinging? valve clatter(normal soob tick)? rod knock?

It's rattling noise (valves?) always at certain rpms, acceleration and also when going uphill. I had tune up done recently, and seems it got worse after that. Any thought?

there will be a "ticking" noise from the lifters if they get old, but is fairly normal.

 

rattling sounds like a ping issue, maybe she is getting too hot, there might be a slight leak in the cooling system, ir possibly a bad head gasket.

 

but running hot somewhere......