usually you would get a cat related code (P0420 primarily) if the cat were below efficiency thresholds. This code is most likely related to the sensors themselves, and/or the wiring to the sensors.northvibe wrote: ↑Tue Feb 11, 2020 7:41 pm My sister has a '10 2.4L however similar issue. THe cel was the downstream sensor, I replaced it, cleared the code, still came back with bad o2. I'm going to replace the up stream sensor now. If that still is bad, I'm wondering if it is a clogged/bad cat, maybe worth checking that.
Good point. Well I hope it is just the o2 and I can get this thing running better. RUnning rich for this long can't be good for it only big HP gainszbyers wrote: ↑Wed Feb 12, 2020 5:03 amusually you would get a cat related code (P0420 primarily) if the cat were below efficiency thresholds. This code is most likely related to the sensors themselves, and/or the wiring to the sensors.northvibe wrote: ↑Tue Feb 11, 2020 7:41 pm My sister has a '10 2.4L however similar issue. THe cel was the downstream sensor, I replaced it, cleared the code, still came back with bad o2. I'm going to replace the up stream sensor now. If that still is bad, I'm wondering if it is a clogged/bad cat, maybe worth checking that.
Sounds like the old Jeep TJ's. If you didn't use Mopar sensors, they failed like crazy. Was just working on my sister in-law's and made sure the mopar parts went in.jolt wrote: ↑Thu Feb 13, 2020 10:31 pm Running "rich" air/fuel ratios is defiantly bad for an engine. The excess fuel will wash down the cylinder walls, removing the oil from the upper piston ring. Since the piston ring is always spinning in the piston ring land, the top piston ring groove will wear out because the lubrication is now washed away. As the groove wears on the piston, you will get ring flutter. The top piston ring can no longer seal properly. Power will drop, oil consumption may increase, and higher cylinder wall wear will also happen. I have seen this before when guys do there own carb tuning thinking richer is more power.
As for the P0135 code, these links may help :
https://www.700r4transmissionhq.com/p01 ... a-corolla/
https://www.toyotanation.com/threads/p0 ... la.282339/
https://www.autocodes.com/p0135_toyota.html
Replace sensors with Denso brand, which is the OEM for this cars electrical system. If you do not believe me see link 2 above. Same goes for spark plugs, coil packs, etc... as Denso designed the electrical and if you do not want strange issues, stick with OEM parts. Check wiring and fuses that are related to the sensor heaters.
try and spray it down with some penetrating oil a few times ahead of time, if you can. o2 sensors love to seize to the exhaust.