p1074 and p0171
My SES light was on for quite some time so I decided to find out what the problem was so I got a code reader and it gave me 4 codes p0171 and p0174 both of these codes shown twice. I cleared the codes and have proceeded to check the codes every time I drive the car. Now I get the same codes but only once and no SES light so I did some research on here and found that it could be caused by a vacuum leak so I went through and checked the vacuum system. I disconnected the vacuum hose from the intake and plugged the outlet on the manifold so see if there was a leak coming from the line going to the break booster. Then I also did the Lines going to the two way valve that connects to the vent control module or whatever its name is. I know there is a vacuum leak somewhere because when I’m driving I will floor the car to pass or something and the heat or AC will switch from the vents to the floor and defrost. After doing so I only got code p0171 I cleared it drove around for a while then both codes came up again. So I am back to square one anyone have any suggestions?
Nope I sure have not! Yesterday I was messing with the vacuum line that goes from the intake to the brake booster and when I disconnected it my car would run like crap sounding like it was going to die! Well lately it has been doing that when I start the car even though the vacuum line from the brake booster to the intake is connected which leads me to believe that it is a rather large vacuum leak! But where can it be?
Last edited by ryanh_3; May 14, 2009 at 02:56 PM.
Well I belive I found the Leak I bought some intake cleaner and as I was spraying it on the intake manifold and TB I sprayed it on the tube going from the intake to the evap canister and it caused my car to almost stall! So I belive the leak is right on the evap canister! will replace and post with results.
I had a similar issue with the cool/heat selector on a '95 3.4L, but mine was going from cool to hot all by itself when I put the blower on highest setting. Turned out some mouse or something nibbled/destroyed a piece that adjusts it, or so the shop told me.
My SES light was on for quite some time so I decided to find out what the problem was so I got a code reader and it gave me 4 codes p0171 and p0174 both of these codes shown twice. I cleared the codes and have proceeded to check the codes every time I drive the car. Now I get the same codes but only once and no SES light so I did some research on here and found that it could be caused by a vacuum leak so I went through and checked the vacuum system. I disconnected the vacuum hose from the intake and plugged the outlet on the manifold so see if there was a leak coming from the line going to the break booster. Then I also did the Lines going to the two way valve that connects to the vent control module or whatever its name is. I know there is a vacuum leak somewhere because when I’m driving I will floor the car to pass or something and the heat or AC will switch from the vents to the floor and defrost. After doing so I only got code p0171 I cleared it drove around for a while then both codes came up again. So I am back to square one anyone have any suggestions?
Post with results, some of us would like to know... ;-)
Well I belive I found the Leak I bought some intake cleaner and as I was spraying it on the intake manifold and TB I sprayed it on the tube going from the intake to the evap canister and it caused my car to almost stall! So I belive the leak is right on the evap canister! will replace and post with results.
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