my system is running too lean and i'm failin emissions, so if you can help me out by telling me who makes these parts for my SH, that'd be great. also may need to replace the o2 sensors. but i'm gonna try cleanin those out first. who should i go to for o2 sensors? the dealer is chargin me two arms and a leg for one o2 sensor. thanks.

 

What mods do you have? First I'd try some injector cleaner. If that doesn't work, you can send them to R&C engineering and have them clean them up for you. I like my AEM fpr, but you have to buy the fuel rail as well, in order to install the fpr without modifying anything else on the car.

 

Need to know what mods you have on the engine. Any major mods may require more fuel than your injectors are designed for.
My recommendations, if you have major mods:
Clean the existing injectors, easiest way is to put a can of BG44K in the gas tank. This will cost about $20.00, don't substitute a cheap alternative.
Check the O2 sensor. The output should vary between 0.25V and 0.7V with an average of about 0.45 to 0.5V. It should go from low to high and back to low every few seconds. If it stays low the sensor is bad or the injectors are two small. There should be a code if the O2 sensor is bad.
If you are still two lean after cleaning the injectors, install an adjustable pressure regulator and increase the fuel pressure in 1 psi increments until the mixture is correct. Don't forget if you test the exhaust after the CAT it doesn't really tell you what the mixture is in the engine.
Why are you failing emissions? NOx too high? Hydrocarbons too high? NOx might be high if you are lean but there are other causes of high NOx.


[Modified by hensley, 11:08 AM 2/14/2002]


[Modified by hensley, 11:09 AM 2/14/2002]

 

What year is your Prelude? There was some government settlment a few years ago that Honda had to make about non-compliant emissions equipment that forced Honda to extend the warranty on emissions-related equipment. This affected 97 Preludes, and maybe 98-99 too.

Do a search on http://www.preludeonline.com - Several people there have had O2 sensors replaced on high-milage cars for free under this program...

Andrew

 

i have a 98 prelude type sh. my mods as far as what would affect emissions are i/h/e, vtec-afc controller, supercharger (the reason i'm running too lean), i know i need more fuel in there. the reasons stated for failing the test are: "system too lean (bank 1)" code p0171, and "o2 sensor circuit slow response (bank 1 sensor 1)" code p0133

the o2 sensors may just be dirty, that's easily taken care of. i just wanna know what fuel injectors, fpr's are available that would correct the "system too lean" problem.

i already poured in some fuel injector cleaner so we'll see how that works out.

thanks for the replies.


[Modified by el_Presidente, 9:12 PM 2/14/2002]


[Modified by el_Presidente, 9:14 PM 2/14/2002]

 

cant you adjust the fuel with the VAFC?

 

i haven't messed with that coz i haven't had my car dynoed yet.

 

Damn I didn't know you have to have the fuel rail in order to install the fpr. How much work will it take to install the AEM fpr without the AEM fule rail?

 

I always thought running the car lean was a sure fire way to pass emissions. Is it because the ecu is throwing a code that you aren't passing? Is it showing up on the test equipment that your car is running lean? Interesting. Hondas run lean around emissions test rpms to get ULEV status. Oh well, reset your ecu and drive the car @ 50-100 miles without boosting, then check for cels. In boost, the JRSC EMS tries to dump as much fuel as it can and may lead to cel triggerring, too lean/rich cels and slow response. HTH



[Modified by G, 10:58 PM 2/15/2002]

 

14.7 stoich is the best a/f ratio for emmissions. That's the reason why cars today try to hit this mark while cruising. The only Honda's that ran real lean was the lean burn Civic VX's and they did that for fuel economy reasons.

Something doesn't sound right. There should be no reason you are running lean. Do you have a leak in the header? Are you sure the V-AFC is set to 0 across the board? Are you sure the O2 sensor is working right?

 

i know one of the o2 sensors is bad, which may be the root of everything. but like i said, it may just be dirty, i'll find that out next week.