<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by John Conner &raquo;</TD></TR><TR><TD CLASS="quote"> The only thing I can think of is that the Ecu's that your friend tried are out of newer integra. As far as I know the 96-98 OBD2a Ecu's are not programed with the code 91 because the 96-98 cars don't have the FTP sensor, and the 99 and up OBD2b Ecu's are programed with code 91 because they have the FTP sensor. also try double checking your wiring. </TD></TR></TABLE>

Well is there any way you could tell if the ecu's are 96 by looking at the ecu #'s? Im most certain the ecu's are 96 cause both of them came out from my other buddies 96 gsr and my brothers 96 gsr. Either someone swapped ecu's w/ them w/out them knowing or something must be wrong.

 

The only reason this code appears when swappiung a 98 GSR engine into a 96-97 EK, is because the 98 GSR has a fuel tank pressure sensor and the 96-97 EKs don't. Putting 96-97 P72 ECU will solve the problem. That is, as of now, the only way I know of solving that problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slixxracing &raquo;</TD></TR><TR><TD CLASS="quote">

Well is there any way you could tell if the ecu's are 96 by looking at the ecu #'s? Im most certain the ecu's are 96 cause both of them came out from my other buddies 96 gsr and my brothers 96 gsr. Either someone swapped ecu's w/ them w/out them knowing or something must be wrong.</TD></TR></TABLE>

I tried sreaching if the searels are different but had no luck, I dont think that you can tell OBD2a from OBD2b by just looking at them sorry.

 

e-kay,<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by e-kay &raquo;</TD></TR><TR><TD CLASS="quote">The only reason this code appears when swappiung a 98 GSR engine into a 96-97 EK, is because the 98 GSR has a fuel tank pressure sensor and the 96-97 EKs don't. Putting 96-97 P72 ECU will solve the problem. That is, as of now, the only way I know of solving that problem.</TD></TR></TABLE>

There is another code 91 fix in this thread.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by John Conner &raquo;</TD></TR><TR><TD CLASS="quote">e-kay,

There is another code 91 fix in this thread. </TD></TR></TABLE>

Yeah sorry about that. Changing the ECU is a cleaner but more expensive way of fixing it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by e-kay &raquo;</TD></TR><TR><TD CLASS="quote">is because the 98 GSR has a fuel tank pressure sensor and the 96-97 EKs don't. </TD></TR></TABLE>

Do you mean the 98 gsr ecu and the 96-7 ek ecu's have a FTP sensor?


So you must have a 96-7 EK inorder to use a 96-7 p72 ecu, am i correct? My buddy has a 98 EK and a 96 gsr engine with a 96 p72 ecu, so the CEL shouldnt even apprear right? Or what ecu should he use to clear it up w/out ativating any other CEL. A 98 p72 ecu since he has a 98 EK?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slixxracing &raquo;</TD></TR><TR><TD CLASS="quote">

Do you mean the 98 gsr ecu and the 96-7 ek ecu's have a FTP sensor?


So you must have a 96-7 EK inorder to use a 96-7 p72 ecu, am i correct? My buddy has a 98 EK and a 96 gsr engine with a 96 p72 ecu, so the CEL shouldnt even apprear right? Or what ecu should he use to clear it up w/out ativating any other CEL. A 98 p72 ecu since he has a 98 EK? </TD></TR></TABLE>

You can still use a 98 p72 ecu w/ a 96-7 EK. The check engine light will just be on. But it won't be in limp mode so it's nothing to be alarmed about.

For your buddy's setup, you're right, the ecu isn't looking for any kind of reading from the FTP sensor even though there is one on his car. So there will never be a code 91.

A 98 p72 ecu would be optimal with 98 EK, but not necessary.

Hope this helped.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by e-kay &raquo;</TD></TR><TR><TD CLASS="quote">You can still use a 98 p72 ecu w/ a 96-7 EK. The check engine light will just be on. But it won't be in limp mode so it's nothing to be alarmed about.

For your buddy's setup, you're right, the ecu isn't looking for any kind of reading from the FTP sensor even though there is one on his car. So there will never be a code 91.

A 98 p72 ecu would be optimal with 98 EK, but not necessary.

Hope this helped. </TD></TR></TABLE>
Yeah I know the car wont be in limp mode, but it's just annoying seeing that the car does have a CEL. Also I dont know if you ever experienced this but with his motor, the car kinda have a little lag..sorta a stress when the motor is punched at open trottle, but when it's driving normal the motor seems fine. Could it be cause of the CEL? No other CEL is reading but for that annoying one.

Also if switching to the correct ecu's doesnt solve the problem and adding the **** doesnt solve the problem, is there any other way to resolve and kill this CEL 91?

 

I wouldn't think that the CEL would have something to do with that. All the CEL does is warns you that there is a pressure leak somewhere in the fuel system. This is there for environmental purposes.

What would cause that kind of lag though, I'm really not sure. I would think maybe dirty injectors or dirty air filter....but don't quote me on that because I'm really unsure.

 

ok..see if u guys can help me on this one..

my car was running fine at first( running open headers w/ cat converter)
after the install of a cat-back exhaust..code 91 appeared?..
what could be the problem?..where can i check for leaks?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EGkwazhimoto &raquo;</TD></TR><TR><TD CLASS="quote">ok..see if u guys can help me on this one..

my car was running fine at first( running open headers w/ cat converter)
after the install of a cat-back exhaust..code 91 appeared?..
what could be the problem?..where can i check for leaks?</TD></TR></TABLE>

Did you get the catback installed in a shop or did you do it yourself?

The shop may have hit the fuel tank pressure sensor or something else on the tank that would make your fuel system leak. I don't see any other reason for this to happen.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by e-kay &raquo;</TD></TR><TR><TD CLASS="quote">

Did you get the catback installed in a shop or did you do it yourself?

The shop may have hit the fuel tank pressure sensor or something else on the tank that would make your fuel system leak. I don't see any other reason for this to happen.</TD></TR></TABLE>

i installed the exhaust myself..its from my bro's 92 EG..so the exhaust is made for EG models..it fits fine though.
also.i have a 96 EK hatch and as stated above these civics dont have fuel pressure sensors..

i just bought a potentiometer though..ill just try that to see if it'll clear up..

p.s.
the guy "john connor" said to solder the wires, cant i just splice up the wires and connect them together?. wont that work just the same?
just making sure before i do anything.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by John Conner &raquo;</TD></TR><TR><TD CLASS="quote">I dropped a 99 b18b in my 96 ek in November. I used the 99 ecu and it keep throwing code 91 fuel tank pressure sensor (FTP). My friend and i figured out that the ODB2A cars don't have the (FTP) and the ODB2B cars do. You can do a couple of things to get rid of the code. Use ODB2A or older ecu, thanks to trey i now know that you can turn your car on count to ten then start it and it will not throw the code, I know that you can also change out the gas tank for one with the sensor, But there is a better way you can trick the ecu into thinking the (FTP) is there.

Problem:
you need to get a grounded D15 pin out when tested with multimeter to read around 2.5 volts.

Supplies: tape, solder, one ecu pin, potentiometer (aka volume ****), and 3 wires (one Yel/Blu, one Lt.Grn, one Grn/Blk)

Explanation:
1.take the Lt. Grn solder to the ecu pin and to the potentiometer.
2.pin ecu pin out D15 with the Lt. Grn wire
3.take Yel/Blu wire solder to the Yel/Blu wire in ecu pin (D10) and to the potentiometer.
4.take the Grn/Blk wire and solder to the Grn/Blk wire in ecu pin (D11) and to the ground on the potentiometer. (the grounds is by it self)
5.use multimeter to set the potentiometer at approximately 2.5 volts.
6.tape up wires.
Caution: do not solder with the ecu hooked up could blow the ecu!</TD></TR></TABLE>

Dude, thanks a lot for this fix. I tried it tonight and it works great. Tuned the potentiometer to 2.5V and no more code 91.

Thanks a lot

 

Another Code 91 & FTP sensor page.

 

marking page...

 

i got rid of 91. now i have 90 anyone find a fix for this problem.

 

ttt