O2 sensor shouldn't have ANY air leaks or the reading would be off and affect idle. Have it welded to seal any leaks.I’ve literally been chasing the SAME EXACT THING for months now and yes, my TPS is set up correctly and I used OEM vacuum lines, new throttle cable and intake tube, etc. and although every step taken did reduce the idle, it’s still around 1k. It always had the high idle since I got it and it passed emissions previously and now won’t, at this point it idles too high to start the emissions test at some places and won’t Pass emissions because of really high HC’s (High CO as well) and now it throws a code 26. Again, everything I’ve done so far reduced the idle a little and it originally did not have a CEL, then went to throwing a code 25/26 combo and after the valve cover gasket and everything from the PCV valve to brake booster hose. I’m going to start just replacing stuff like the Fuel Pressure regulator (my vacuum line seems plugged on it?) and possibly the EGR valve at this point. Would pin holes by the o2 sensor cause a vacuum leak because that’s what all signs point to?
That statement scares me because my exhaust is pretty rusted, my o2 sensors test fine but when I eventually need to replace them, those things aren’t coming out due to the rust so I’m thinking I may eventually have to relocate to the PAIR valve exhaust ports. What really sucks is I had a set of new o2 sensors that I sold a few months ago because mine tested good, which I could have used to test this out (my uncle gave them to me, he had a NOS set from back in the day just sitting in the garage from an old 80 project).O2 sensor shouldn't have ANY air leaks or the reading would be off and affect idle. Have it welded to seal any leaks.
Yeah that's kind've what I figured. On startup then, is it normal for the plunger to suck all the way in? The screw should/ or shouldn't be resting against it at idle?Also, that screw you were messing with is a dashpot. It keeps the throttle plate from slamming shut when you let off the gas abruptly.
I did clean the throttle body when I had it off. When I was done I didn't see any more buildup or grime if I recall. I did clean the hell out of the IAC when I had it off, too. Really hoping that itself isn't bad because I know they are decently costly. Hopefully after I get the TPS set here this week It will point me in a better direction.Did you clean your throttle body when you had it off? I mean did you clean all the carbon out and did you clean the edge of the throttle plate also? Carbon on the edge causes plate to be open more driving up idle. IAC has a harder time controlling idle because of this.
Doing this really helped with my high start-up idle and also helped with warmed up high idle as it returned it to 650. I also cleaned the IAC and reset the TPS.