Any of you guys know a simple way I can fake out this sensor? I need to get this car to pass PA emissions and this is the only code I'm throwing. I know I can have it tuned out of the computer but are there any other quick fixes?

 

Nobody? Does this mean everyone just gets this tuned out?

 

Which sensor are you talking about, the one in the Fuel tank for pressure ? Not completely sure, but I think the PCM needs inputs from the pressure sensor and maybe the fuel level ..?

you can try and use the OEM sensor and rig it up so that is does output a reading to the PCM, just hide the sensor so the inspector doesn't see it. (?).

 

Please leave it intact it is a very good vent system for the fuel tank and keeps it from smelling like fuel. You can relocate the sensor anywhere to get it out of the engine bay but leave it intact.

 

I would like to leave it in tact but I don't know how to make it work. I am referring to the sensor mounted on the intake manifold(on trucks anyway). I guess I need to be schooled on the operation of the EVAP system and see if I can adapt it to my car(01 Mustang). I do know that it is a venting system for the gas tank vapors,I just don't know how to make it work with the Mustang tank. Is it as simple as splicing a "T" into one of the existing gas tank vents? Please school me.

 

its very simple there is a pressure sensor at the tank to measure pressure and vacuum, a vent solenoid at the tank and then a purge valve at the intake manifold. it can close the system off by shutting the vent and pull vacuum by opening the purge. the pressure sensor tells the pcm if this is working and correctly by pre determined values based on load of the engine, purge duty cycle and fuel level coupled by time. also knows how long it takes the vacuum to decay in a closed state and with the vent open. its going to take a bit to trick a system like that.

your going to either have to set yours up like this or tune it out

 

89 formula got it right - the system is fairly basic.

if the vehicle you swapped it to already has a vent solenoid there is a good chance you can just wire it up and it will work with the ls harness. you'll need a GM fuel tank pressure sensor for the fuel tank hooked up as well as your evap purge solenoid in the engine bay plumbed from the fuel tank.

you'll also need to either hook up a fuel tank level sender that fits the ls expected range *or* wire in a resistor that falls within the spec for the fuel tank level that will run an evap purge system test - a 100 ohm resistor between ground and the fuel tank level input on the PCM works great.

I don't know why more people don't plumb the emissions systems on their swaps - it isn't that much extra work and you usually pick up a tiny amount of mileage and less codes to deal with/delete

 

Tongboy, I realize this is old, but I'm hoping you're still around and kicking or maybe someone else can help me.

I've seen your information in the BMW forums, great job. Seems like the BMW guys are the only group who cared enough to actually get the EVAP stuff figured out.

I'm hoping you, or someone else, can help me get it figured out for my s2000 LS1 swap. None of the Honda guys have done it, this is still a very low volume swap, and those who've done it don't even bother (like most of the Honda community for that matter).

Mine is in a 2005 S2000. It's got factory unmodified evap system, of course.

I cannot identify exactly how the s2000 evap functions other than it's 0-5v on the solenoids much like the LS1 stuff, and that the purge solenoid on the motor (purge valve as called by Honda) is normally closed with 0 voltage. There's virtually no specific info out there because none of the Honda guys bother, even when going turbo on their factory motors. They just yank it all out.

So if I understand your explanation, should I theoretically be able to 1) plumb the factory EVAP line from the back of the car to the LS1 solenoid on the intake manifold 2)install a GM fuel pressure sensor (how exactly is this installed? Do I have to drill into the tank and install it somehow?) 3) trick a GM fuel level sensor with a 100ohm resistor and it might work?

What about all the other Honda components that are still hooked up to, some of them connected to the Honda ECM? Honda fuel tank pressure sensor, EVAP Bypass Solenoid Valve, EVAP Canister Shut Valve?

My concern is that each of these sensors will need to be properly actuated for the entirety of the system to operate. I can't find enough detailed information about any of these to make a strong determination on if I'll be able to make it work.

I don't want to constantly be smelling fuel or having to worry about pressure/venting the gas cap etc.

 

To the OP, i dont mean to hijack the thread. sorry

Hi Jonathan. I'll probaby PM you with same info in case this gets deleted by moderator.

I'm in the same boat. I got the swap done in 2013 (from 04 gto and i have an 04 ap2) and smog will be due for me next year. I've been to the ref and I want the car certified in california.

Let me know what you have done if you got the evap to work. especially with the fuel level. my fuel level reads zero in hptuners but reads appropriate in the s2000 cluster. I'm like you I"m running both honda and gm ecu.

are you also sending out the speed sensor signal only to the cluster or both the cluster and the GM ecu.

i'm unable to clear readiness monitors with the drive cycle becuase i need mph and fuel level. Mph probably will get signal off the honda sensor to gm ecu, and fuel level I need to figure out a way to send signal to ecu. would prefer to send signal and correct/calibrate in hptuners vs just putting resistor to fool ecu to read a level from 1/4 to 3/4 full

 

I have not gotten the evap to work.

In fact I haven't even messed with it one bit.

My understanding of the evap isn't good enough for me to start hacking stuff or testing. I'd rather let someone smart figure it out, and I'll just pay them.

and I know nothing about HPtuners!

Problem is I can't get someone smart enough to figure it out, lol.

Well, more specifically...nobody is willing to even try. I've heard "you don't need it" literally 100 times. Go figure.

I KNOW it's possible. I just don't know how to do it 100%...like I said in my post, the BMW guys have figured out most of it. I just don't understand exactly how the honda system works in relation to the GM system, and the data just isn't available online. I posted in the s2k forum and someone just attached a picture of the EVAP system layout...not very helpful at all. I don't think many of them even know the intricacies of the Honda system so they're just as blind as we are.

I hope you can get your car to pass. And if you do ever figure it out, please post back in this thread!!!!

 

I'll post back when I figure things out.