I have a poorly fixed exhaust leak between the manifold and cat on the left side of my engine. Long story short, I got a piece of pipe with the flange and O2 sensor mount and have them clamped together with one of those metal band repair clamps. The cuts are not perfect, and it definitely leaks a good bit upstream of the cat and O2. after it had been driven a while with the full break, the O2 sensor was shot, so I replaced, it, but it is now showing bad again (P0134). The vehicle runs open loop all the time, my scanner says sys failure. I have also recently been getting an occasional P0300, random misfire that causes the check engine light to flash.
Could the leaky exhaust be causing the O2 failure? and could those together cause it to misfire. It never runs rough even when it says its missing, so it isn't anything horrible. Maybe poor O2 calculations fouled up my plugs on that side of the engine? if I clear the code and make it try to run closed loop, it goes pretty crazy on the fuel trim, saw it running +50% under acceleration. I'm assuming this is because of nonsense data from the O2 sensor?
Could the leaky exhaust be causing the O2 failure? and could those together cause it to misfire. It never runs rough even when it says its missing, so it isn't anything horrible. Maybe poor O2 calculations fouled up my plugs on that side of the engine? if I clear the code and make it try to run closed loop, it goes pretty crazy on the fuel trim, saw it running +50% under acceleration. I'm assuming this is because of nonsense data from the O2 sensor?