Back in June, I got the news one of my cylinders was effectively dead (a compression test indicated that the #4 cylinder is compressing at 50% to spec). Well, the car still has a lot of life left in it, but who knows how long the good times will continue to roll. I have some work that needs to be done besides the cylinder including reaplacing the O2 and speed sensors and the catalytic converter (not sure off hand which one needs to be replaced). My '97 Protege' was purchased brand new with only 10 miles on it and is still delivering reliable service whith a bad engine and 215,000 miles on it. Way to go Mazda!

 

Thats good the cars still running! There is a problem if you replace the other parts without addressing the compression problem. It can damage the possible new cat converter and o2 sensors if not running correctly. The low cylinder will run richer and that is an enemy to the converters and any exhaust related sensors. Do you know where the compression is escaping...the piston rings or valves?

 

I'm not sure where the compression is escaping, but our mechanic has advised me that the car needs a new engine. Right now, I need to be able to pass the State emissons test so that my registration can be renewed (yeah dude, I got a summons, if I get this taken care of before the court date, everything will be ok and I'll have time to decide the fate of this car). Speaking of cat converters, are those universal ones any good?

 

I would think there is no problems with a universal cat. They do have to meet all emissions standards to be able to sell them. Just look for one with the same exhaust tubing size.