Hello guys i'm out of ideas. i need to see if you guys can help me before i take it to dealer for a whooping $180 dollar diagnostic lol. it's not my car its actually my mothers. i have done all maintenance to it since 90k miles. now has 198k. have done spark plugs,ignitions coils, carbon clean the valves, intake manifold gasket and plenum gaskets. she got the code last month when i look it up of cours says it can be possible things. i replaced the maf with and oem new one, cleared code nothing. came back. then i replaced the pcv valve on bank 2 it had carbon on the tip and looked kinda bad. replaced with oem new one code came back. says is running to lean on bank 2. will and oxygen sensor cause it to run lean on bank 2? have not replaced that yet but i want to kind of know where to look next. help very appreciated.

 

A freind of mine had P0174 on a Lexus IS200, ended up being a bad injector, but he also got misfire codes aswell

 

Could be a leaky exhaust that is causing air to enter the exhaust around or in-front of an O2 sensor, thus causing odd readings.

 

So i have not replaced 02 sensor at all. Theres are 2 upstreams and 2 downstreams. So bank 2 would be drivers side. So should i replace both upstreams and downstream 02 sensors? 🤔

 

Anyone else have this code?or know something?

 

Check for exhaust leaks. In my 2nd gen gs replacing exhaust flange gasket fixed it. Good Luck.