P0171 and P0174 --> crossover vacuum hose (valve cover to valve cover)
08-13-2007, 06:56 AM
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P0171 and P0174 --> crossover vacuum hose (valve cover to valve cover) Good morning everyone!
I am having a problem with the Z at the moment. Recently my car spat two codes at me. Which are P0171 and P0174 which means both banks are running lean. I cleaned the MAF and throttle body again (had done this 5k ago) and I am not using a K&N air filter anymore but just a plain regular FRAM filter. The car is running better now but still idles rough from time to time. I driven the car a bit and the SES light didn't come on just yet.
This could also be caused by a small vacuum leak or restriction I believe so there is where I have a few questions. Last year I had a vacuum leak at the crossover hose (hose is located on the far back of the engine connecting both valve covers together). I brought the car to a gm mechanic and he replaced the hose with some pieces of fuel hoses connecting it to the already existing stock plastic hose. It seems to me that this hose is collapsing under the pressure... at least that is what it seems to me. I am not sure if this could be the cause of the problem or not but it's definetely something to be looked at. Should I purchase a stock piece of hose? Or can I get something better then that?
The 98's are a little burried with vacuum hoses :S
I am having a problem with the Z at the moment. Recently my car spat two codes at me. Which are P0171 and P0174 which means both banks are running lean. I cleaned the MAF and throttle body again (had done this 5k ago) and I am not using a K&N air filter anymore but just a plain regular FRAM filter. The car is running better now but still idles rough from time to time. I driven the car a bit and the SES light didn't come on just yet.
This could also be caused by a small vacuum leak or restriction I believe so there is where I have a few questions. Last year I had a vacuum leak at the crossover hose (hose is located on the far back of the engine connecting both valve covers together). I brought the car to a gm mechanic and he replaced the hose with some pieces of fuel hoses connecting it to the already existing stock plastic hose. It seems to me that this hose is collapsing under the pressure... at least that is what it seems to me. I am not sure if this could be the cause of the problem or not but it's definetely something to be looked at. Should I purchase a stock piece of hose? Or can I get something better then that?
The 98's are a little burried with vacuum hoses :S
