Alright so about 10 days ago I notice my cars seems a tad slower. Hhhhhmmmm. So shortly thereafter I'm out driving and I get a blinking CEL- blinking in random patterns as if it's morse code. So I park it for the night, check for codes the next day and get code 0505- no diagnosis. I drive around ~40 miles more, no more CEL. I check for ghost codes and get 3 of them: 0702 (Three way catalytic converter) 0304 (knock sensor) and 0504 (transmission communications line.) I reset them and over 100 miles more of driving later, I still have code 0304 (knock sensor) and 0504 (transmission communications line.) Odd. Gas mileage is sucking, acceleration blows (RPMs aren't match MPH like they should), car has rough starts (gotta turn the key twice usually) tons of soot in exhaust-- seems like it's running in safe mode. I surmise this could be an O2 sensor problem...or do you think it's the coil pack? Mass air flow sensor? Bad battery? Any advice appreciated, thanx!!

 

0304 is the knock sensor. If it's bad your performance will suck. People also say it gives poor gas mileage when bad, but I didn't notice any change in that.

 

Damn ya know there's so many different things that could be going wrong here. Looks like it'll hafta go to the stealership for a diagnosis. Time to not have the car for a day and get ripped off. I'm also very afraid the dealer will mis-diagnose the problem intentionally and make it out to be a lot worse than what it is. Just like how they wanted $2625 to fix an oil leak that was a $10 job I could do myself. Lovely.

 

They will try to charge alot to do the KS because they take alot apart to get to it. There is an easier and faster way so just do it yourself.

 

If this is a knock sensor issue, where did code 0702 (three way catalytic converter) come into play?
If this is an O2 sensor issue, how comes I no longer have code 0702 (three way catalytic converter)?
Self-diagnosis is so limited these days...