Okay so my cel came on about 3 weeks ago and i got my mechanic to see what it was and it came up 2 upstream oxygen sensors and an egr valve. So I ordered the parts and got them 2 days ago. My car has been running like nothing was wrong with it (except stalling when I switch to reverse, but it has always done that, does it even more when i give it some gas while in reverse) until 2 days ago. I started stalling at every red light i came to or whenever i stopped pretty much. But im pretty sure thats because of the oxygen sensors. But then when I went to drop my car off at my mechanics last night the person following me said i was shooting out smoke every now and then. So my question is, is it because of the oxygen sensors? I told my mechanic and he said its probably running rich because of the o2 sensors and that he would take a look at it. So would the sensors cause that or do I have another problem to worry about? Also, when the idle was falling and I tried to give it some gas to get it up I heard a grinding noise come from around the left side of the engine bay and the idle didnt go past 1500 and ended up dying anyway.

 

Clean out your Throttle Body. It should be done every once in a while. I do it with some Carb Cleaner and a brand new Terry Clotch Towel. Search the .org for TB Cleaning and it'll solve your problem. That stalling gets dangerous. Catches you at the worst of times. Happened to me first when I was going around a turn. I think I had to change my shorts after that one. I clean my TB every oil change. Just a habit helps out alot. You'll notice a more smoother idle.

 

dont use carb cleaner.. .. .. ..they make spray cans of throttle body cleaner-they make it to use on...throttle bodies...carb cleaner is strong and not worth risking that stuff eating up hoses from run-off or screwing up the coating in the TB...i used a can of TB cleaner and it worked perfect...i did it 2 weeks ago and STILL gettin high idles at cold start-up..bout 1200rpm...hmmm

 

could maybe also be your maf that is messing up....

 

Yeah I heard a couple people say the maf for my stalling in reverse problem, also heard tranny but wouldnt it stall all the time right when I switch to reverse instead of just sometimes? And usually it doesnt stall in reverse unless I give it some gas.. And my throttle body was recently cleaned so I dont think thats it. Im pretty sure the stalling while at a stop is due to the o2 sensors since I ran into a guy who had the exact problem in a 99 max and it was an o2 sensor. But I have no clue what the grinding noise was about. When I was at nissan I told the guy at the desk about my stalling in reverse problem and he said IACV should be replaced which I already replaced, so he said to reset the ecm. Also is the smoke problem caused by the bad o2 sensors?