running a mopar perf. pcm and no downstream o2 sensor will result in what?

 

touchy subject... I have my senser hooked up but not in the exhaust pipe... i know i tell everyone to drill a bung but I dont have any codes and I have good mpg's... So its hard to say... if you disconnect it its going to throw a code...

 

yeah - it throws a code for sure. my mpgs actually picked up when i installedthe perf. pcmand stayed improved. i am nearly positive that the pcm responds to no downstream 02 sensor by providing a defualt air/fuel mixture - instead of adjusting it depending on its readings.now i cant rememberlead me to this and its making me uneasy.

got a decked, clean block with 90k on it and a head with 60k on its way. what else should i replace while my back porch looks like my engine bay? anyone know where to get the hard heater lines?

 

talk to i ride neon he has like 3 blocks laying around and he may have the heater hard lines... acually i know he does i was going to pick them up for a 2.4 swap...

but back to the downstream o2 sensor...

it is used for 2 things...
To make sure your cat is installed and working properly...
and for long term fuel trims... ie long trips over 300 miles where your going the same speed for long periods of time... kind of like a fine adjustment to your A/F ratio...

 

so it would lighten the fuel input since the engine can maintain speed w/out as much?

 

i wouldent say that... it really dident make a difference on my 350 mile trip to boxers to do his install I still got 37mpg on the two tanks that I used one there and one back... I really dident see much a difference at all...

If your asking if it will lean you out at cruzing speeds like the honda's new lean vtech thingy no... it simply smooths out your a/f ratio so it burns less fuel... In stop and go traffic the a/f ratio is all over the place all the time... on the highway its not so it says ok well I'm going to be going this speed for a while lets smooth things out so I burn less fuel... I mean its not going to make your mpg go threw the roof just a few mpg more...

 

Mopar PCM looks for the downstream O2 sensor.....AF/x PCM does not!

 

gotcha. even if my o2 sensor was plugged in and in the system it woudlnt be happy cuz the cats gone. i dunno. i guess its not gonna be a major problem.

since i wont make it to the job i had lined up for the 15th, im gonna just do some repairs while my car is down. my grandma wants me to get all things neccesary so that i dont have any problems when i get to college in the fall. i already got my new tools - which has made this actually fun instead of a pita

while this is nice - to be able to get new stuff - i dont want to break her. ya know? can someone check this clutch out for me? have u ever head of valeo or anyone using them? its pretty cheap and its non-modular like i need.

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