whoops?....89 dodge van

From : rod betty jo

Q: peter can anybody tell me exactly how chrysler pcms determine fuel mixture lean condition im running dodge durango 99 on propane and pcm consistently throws p0171 condition. propane computer autronic feeds emulated o2 sensor signal into vehicle pcm and allows me to set emulation parameters time low 0v and time high 1v. ive tried reducing time low to simulate richer mixture but to no effect. this has no effect on driveability btw... just would like to turn that damn check engine light off. it will always re-light after a couple of trips. buy a performance chip and a programmer and custom program your vehicle. sarge .