SpeedPak

This goes out to all the real tech gurus out there.
There is a chance that myself and my s2k (02 sebring silver) may be making a move to a place where only high octane (100+) leaded gas is available. There are NO emmissions worries but i need to know exactly what i need to modify to make this work. I know the cat will have to go, but are there any test pipes out there that will run w/o throwing codes. Also what ECU changes need to be done and how do I do them. (meaning where do i get a new ecu)

if there is anything you guys can give me as far as info would be great

thanks guys

fais

Bobway

I would think it would be easier to find an unleaded race fuel, like VP Racing Fuel. They have a website with info on their fuels and local dealers/distributors.

The Reverend

You could use the AEM ecu (plug and play) so you wont have to worry about the test pipe throwing a code. But you might also have issues with O2 sensors getting messed up from the leaded gas. Dunno how you get around that one.

marcucci

The test pipe can be fixed with either:
- pulling the ECU backup memory fuse (it will forget the pipe is a problem before it is a problem)
- Applying a resistor in line (10M I think) with the return signal to reduce it's amplitude

The biggest issue I would think is the O2 sensor; it will foul with leaded gas from what I understand. I'm not sure what you can do, other than replace it as a maintenence item (30kmiles? 60k miles?).

Utah S2K

Agree with Mar here. Your biggest issue will be with the O2 sensor....specifically the post catalytic one. OBD-I (prior to 1996) was originally designed to detect electrical failures in PCM sensor inputs. OBD-I did not test the catalytic converter. OBD-I systems did not protect the converter. This all changed in 1996 with the introduction of the OBD-II system. It's primary task is protecting the catalytic converter from damage. It does this by monitoring feul, misfire and catalyst efficiency. This requires sophisticated embedded software in the ECU and is based on the addition of a downstream (i.e. post catalytic) O2 sensor to measure catalyst effeciency. I'm afaid to say you'll have a lot more to deal with in this conversion then thrown codes.........

Utah

SpeedPak

the issue in its entirety is quite simple: the car and I are moving to pakistan, where unleaded premium fuel is next to impossible to get. the only fuel that is 93+ is leaded.

What are the repricusions of fouling up an o2 sensor?
I am most concerned about valve damage due to the leaded fuel, which to avoid will have to be handled by some sort of modded ecu program to take it into effect.

thanks
fais

marcucci

The O2 sensor regulates the a/f mixture. When they are "fouled" (usually in the form of excessive deposits) they usually report a lean condition, ending up in an engine running rich. The repercussions are reduced fuel efficiency and power, and will eventually lead to plug fouling, carbon buildup, and eventually, a check engine light (probably a run-rich or O2 fail condition).

The cure would be replacing the O2 sensor at a certain interval; what, I'm not sure of. They are relatively easy to get to and change, and run I think US$130. The pre- and post-cat ones should be the same.

This gets into what Utah said... I don't think you'd have to worry about the cat so much if the O2 sensors were good, but it might be easiest to remove the cat as you suggest and just replace the O2's with some frequency. I'm pretty sure that leaded fuel and O2 sensors were never mixed, but I know that catalytic converters and leaded fuel were; what I'm not sure, though, is if the high-tech cat on the S2 could last. I would just remove it and not hassle with it (I assume Pakistan doesn't do emissions testing! ).

Quote:

I am most concerned about valve damage due to the leaded fuel, which to avoid will have to be handled by some sort of modded ecu program to take it into effect.

I thought it was the other way around- engines requiring leaded fuel that ran on unleaded suffered valve damage... I wouldn't think you would have to worry about that on this car. I believe that for a "leaded" motor the valve guides/seats required leaded fuel for proper sealing, I am not sure that leaded would be a problem in itself. Granted, I'm youg enough that I've never cracked open a motor that ran on leaded, so...

You might contact Honda, they might be able to put you in touch with someone. It's probably safe to say that Honda doesn't sell too many S2's in Pakistan, but there might be another place using leaded that they do. I'm sure someone can get you in touch with someone that can comment on the repercussions. If not, you might try hunting on the internet about converting for leaded use (or not).

Good luck... and I hope this is something good for you. Pakistan isn't a place I'd want to be right now!

Bobway

You should check a little on how they rate the octanein Pakistan as well. If it is the Research method, Motor or ROM (road octane method R+M/2). The octane in unleaded over there may actually be higher if you use the same method to measure that is currently used here.

Wouldn't it be nice if it weren't a problem after all?