code that comes and goes

[bird of fire]

about a month ago I go this code P0153 Heated Oxygen Sensor (HO2S) slow response Bank 2 Sensor 1. I cleared it and got this code this P0174 Fuel trim system lean Bank 2. When I got the lean code you can smeal the unburnt fuel. I put in a mid grade fuel instead of regualr and the code went away for 2weeks. Then I got this code again P0153 Heated Oxygen Sensor (HO2S) slow response Bank 2 Sensor 1. When I started the car now it's idle is a little higher then normal by 100 to 150 rpms.When the car heats up the idle is normal. This all happens after i got rid of the egr vavle I put the block off plate and did the simulator too. Some one please help!!!

[slow6]

Re: code that comes and goes

blocking off the egr might trick the maf into reading rich.
but anyways it sounds like that passenger sensor is going out?

[bird of fire]

Re: code that comes and goes

I changed the 02 sensor when I got the code the first time.