Cel 2772, 2771

[Iyzmi]

I was driving on the highway today and got a CEL. Pulled the codes with Carly and got:

002772 Activate tank vent valve
002771 Lambda-probe dynamic diagnostic Vcat

The car is running an ESS 550 supercharger and stock exhaust. I did some searching and it seems like pre-cat O2 sensors may need to be replaced but the tank vent valve description is throwing me off, what does that mean? Do I need to replace both pre-cat O2 sensors or is there potentially some other issue here like the fuel tank breather valve?

Looking through my service records I found that the bank 2 pre-cat O2 sensor was replaced 10k mi ago.

[Iyzmi]

bump.

[Patrón]

Originally Posted by Iyzmi

I was driving on the highway today and got a CEL. Pulled the codes with Carly and got:

002772 Activate tank vent valve
002771 Lambda-probe dynamic diagnostic Vcat

The car is running an ESS 550 supercharger and stock exhaust. I did some searching and it seems like pre-cat O2 sensors may need to be replaced but the tank vent valve description is throwing me off, what does that mean? Do I need to replace both pre-cat O2 sensors or is there potentially some other issue here like the fuel tank breather valve?

Looking through my service records I found that the bank 2 pre-cat O2 sensor was replaced 10k mi ago.

the vacuum line for the blower is connected to the tank vent valve. check there for tears, disconnection or other types of problems. do you have a boost gauge and are you getting vacuum readings?

no clue what that second code is related to.

[Iyzmi]

Originally Posted by Patrón

the vacuum line for the blower is connected to the tank vent valve. check there for tears, disconnection or other types of problems. do you have a boost gauge and are you getting vacuum readings?

no clue what that second code is related to.

Yeah, that tank vent valve is only $80 so I'm tempted to just replace it if I already have the car apart to look at it. Just odd that I don't have any of the symptoms associated with that part failing (as noted in the DIY replacement thread). I do not have a boost gauge.

The second code seems to be related to the bank 1 pre-cat O2 sensor. If that diagnosis is correct, it may explain why my car only put down 445-450rwhp when it should've come closer to 470. But that may also be a long-shot.

These codes don't seem related despite being sequential numbers. Trying to figure out if one can be triggering the other before needlessly replacing parts.

[Patrón]

Originally Posted by Iyzmi

Yeah, that tank vent valve is only $80 so I'm tempted to just replace it if I already have the car apart to look at it. Just odd that I don't have any of the symptoms associated with that part failing (as noted in the DIY replacement thread). I do not have a boost gauge.

The second code seems to be related to the bank 1 pre-cat O2 sensor. If that diagnosis is correct, it may explain why my car only put down 445-450rwhp when it should've come closer to 470. But that may also be a long-shot.

These codes don't seem related despite being sequential numbers. Trying to figure out if one can be triggering the other before needlessly replacing parts.

if you didn't have a supercharger, i'd say just replace it but since the vacuum line is tapped into that part (if i remember correctly) the problem may be the vacuum line connection. sometimes it crimps, depends on how installer connected it. since you're taking the manifold off anyways, might as well replace it but i'd look to see what's going on in there before replacing the part.

these cars eat O2 sensors. wish someone would come up with a solution to why so many O2s go out.

[Iyzmi]

Does anybody have access to the code information for 2772? It's not in the CEL sticky like 2771 is:

http://wiki.rcollins.org/core/index....r:_2771,_P0133

I've been told 2772 is actually not related to the tank vent valve and is something involving the bank 2 O2 sensor.

[777eThOd*]

Bump for more info, My VF650 popped up some codes and 2771 was one of them. Was random to cause I had just turned it on and I was starting to move it and all of a sudden I got the SES light. My reader read 2771 , 2712 , 27AE , 2B58 and 27B2. I had just filled up the night before so I took the gas cap off and tightened it back up and cleared the light. Then the next day I took it out the garage and drove it and beat on it and nothing yet. I feel no power loss as well. I'm guessing maybe the Pre-O2 Sensor is on it's way out. So far so good. But I'm wondering the difficulty of how it would be to change it out.

[777eThOd*]

I'm also at 48k miles and have ran race fuel but have been on pump recently. So i'm guessing the O2 Sensors lol... I might just change it out now cause TX2K17 is around the corner..

[SonnyJack]

Originally Posted by Iyzmi

I was driving on the highway today and got a CEL. Pulled the codes with Carly and got:

002772 Activate tank vent valve
002771 Lambda-probe dynamic diagnostic Vcat

The car is running an ESS 550 supercharger and stock exhaust. I did some searching and it seems like pre-cat O2 sensors may need to be replaced but the tank vent valve description is throwing me off, what does that mean? Do I need to replace both pre-cat O2 sensors or is there potentially some other issue here like the fuel tank breather valve?

Looking through my service records I found that the bank 2 pre-cat O2 sensor was replaced 10k mi ago.

Currently getting a CEL and these same two codes; 2771 & 2772.

According to my reader it's the pre-cat O2 sensors on both banks. Says they are not present so they're completely dead or I've got some kind of electronics issue. Since replacing them is easy I'm really hoping just dead. However, I replaced them both in June 2016.

Been SC'd for past 4,000 miles (Nov 2016) so hoping this is a one off and not something to look forward to on a regular basis.

[Iyzmi]

Originally Posted by SonnyJack

Currently getting a CEL and these same two codes; 2771 & 2772.

According to my reader it's the pre-cat O2 sensors on both banks. Says they are not present so they're completely dead or I've got some kind of electronics issue. Since replacing them is easy I'm really hoping just dead. However, I replaced them both in June 2016.

Been SC'd for past 4,000 miles (Nov 2016) so hoping this is a one off and not something to look forward to on a regular basis.

I cleared the codes and they never came back. Try that first and if all else fails go ahead and replace both pre-cat O2 sensors. That's my plan.

[SonnyJack]

Originally Posted by Iyzmi

I cleared the codes and they never came back. Try that first and if all else fails go ahead and replace both pre-cat O2 sensors. That's my plan.

Yep, tried that and they came right back. My reader has a "live" mode and I'm getting zero data from the front two sensors. Seems strange to me. Gonna replace them this weekend and see if that helps.

[Iyzmi]

Originally Posted by SonnyJack

Yep, tried that and they came right back. My reader has a "live" mode and I'm getting zero data from the front two sensors. Seems strange to me. Gonna replace them this weekend and see if that helps.

Did replacing them help?

The codes never came back for me but I'm considering swapping the O2 sensors anyway before taking my car to the dyno in a month or two.

[SonnyJack]

Originally Posted by Iyzmi

Did replacing them help?

The codes never came back for me but I'm considering swapping the O2 sensors anyway before taking my car to the dyno in a month or two.

Yep, since replacing them I've had no more issues.