I have a 98 V70R, it has ran flawlessly the last 3 years. Some light mods, and maintaining it pretty religiously but she has me pretty confused.. about 3 months back I was driving it home from work nice and easy on the highway, and I noticed the wideband hitting about 16-1, extremely out of the ordinary.. so I just took it nice and easy the remaining 15mins home, no engine light as yet. Being curious I took it for another drive to see if I a check engine light would pop up, and about 10mins in I got the engine light I was waiting for, P0130. So I ordered a new OEM sensor as I had done roughly 100k in the car since buying it anyways. And checked for vacuum leaks, couldn't find any leaks at all inspecting and spraying brake cleaner all over the place
So after I stalling new O2 sensor I drove the car for a day or 2, still running rich, stuttering a little decellerating nearing a stop, not getting into closed loop at all..
Since this I have installed a new OEM MAF sensor, cleaned out the PCV, cleaned idle control valve smoke tested the car twice and cannot seem to find a vacuum leak anywhere! Fuel pressure is also holding solid just over 3bar.
For the most part the car starts up perfect, cold or hot. Then after running approximately 6-8 seconds the AFR's will drop to 10-1 at idle, but in saying that it can be rather Intermittent, disconnecting the battery overnight to make sure the electrical system is fully discharged the cat can start up and idle about 12-1, then go back to almost normal.. using the torque app to monitor the O2 voltage is sweeping spot on and AFR is 14.7, then a couple minutes the O2 sweep starts dying off to ultimately flatline and car is back to super rich.. kind of running out of ideas as to why this can be. Ant help is greatly appreciated! P.S also has new coolant temp senor
