Was getting code for po155,161,113,141,135,300. I change all 6 sparkplugs and all four o2 sensors. the car runs very smooth now but after about ten minutes of driving the check engine light comes on but the car is still running fine. the codes diplayed now are po132,138,158,135,141,155,161. these all relate to some problem with the o2 sensers. could a clogged up injector fool the o2 sensors. ive been told by the dealership that iam way over due for a cleaning service. my engine is a 2.7 flex fuel 2008 avenger