Hey guys, went to a friends house today and all was good but on the way back home i noticed the aem wideband was showing some weird readings. The car drives and idles just fine as it should. I noticed that driving 80mph in 5th gear it was reading 10.9 - 11.5 so im like wtf. This was just cruising. I let off the gas and it would stay around 12s when it has always went all the way lean showing ---. At idle it was showing 11s so i get to a light a bleep the throttle some and try different things and it started going --- when letting off the gas but cruising readings were still weird. I bought a bosch sensor about 6 - 7 mo ago or so brand new. Im going to do the brake clean on rag test tomorrow but my question is a car idling at 11s or cruising at 10s or 11s wont sound/feel nice and smooth like its usual self correct? Yesterday, i used the 2 step a bit since i got a new exhaust was just messing around with it. Maybe this can hurt the sensor? It is mounted quite a ways down the downpipe maybe 18 - 20 in from turbo. Any suggestions and opinions would be appreciate it.

*note : been doing some research and people have used a bosch 02 sensor from the auto parts stores instead of aems sensor... bosch part # 17018...people say it is the exact same sensor and it plugs right up...it is also much cheaper and comes with a warranty from the auto parts store...have any of you guys used this sensor and has it worked correctly?

 

It used to happen to me on MAF quite a bit though I can't contribute it to one thing.the car drove fine for a while like that. Also ruled the WB02 out as being the culprit. But the car went through a a lot of changes at one time so like I said can not contribute it to any one thing . Oh, can tell you in my case it wasn't the factory Front O2 sensor either, confirmed with a new sensor, that new sensor is still in the car doesn't do that anymore after said changes.

Though I do get a rich idle sometimes, spools a bit rich, seems to be temp dependent. So I believe a simple retune will resolve that. I hope lol.

I don't know your tuning knowledge but maybe get some logs and consult a remote tuner OR maybe open a new or move thread to the ECUFLASH subforum and post the log/s up.

Even if it is a mechanical issue a lot of times it can be narrowed down a little easier seeing the logs and maps. Make sure to log all pertinent PIDS

 

not very experienced with tuning...the afrs would change a bit depending on temp but they never did this...i mean 11 cruising in 5th and idle i would guess the car would rub like **** but it ran as it always did...

 

You've already answered your own question.

It's to do with the pump and the pressure.

This is the 4th thread you've started with the same problem

https://www.evolutionm.net/forums/ev...re-issues.html

https://www.evolutionm.net/forums/ev...-question.html

https://www.evolutionm.net/forums/ev...mp-issues.html


You KNOW that the pressure is still too high.
WTF do you expect to happen?


Maybe it's time to part it out and buy a Honda?

 

so I've owned this car for years with the same setup and has never done this...now all of the sudden the wideband reads 11 at idle and cruising and when letting off the gas it doesn't go lean to ---...all this while still running perfectly fine and you want to say it's the pump? Not even a possibility that the wideband sensor or hell maybe even front o2 sensor...you even took the time to look up the other threads...if you put all this effort into trying to help people instead of trolling you may actually help someone figure something out...

*note - this is not the same problem as the other threads...

 

front o2 sensor wasnt working...replaced with new one and now idle is lean as ****...i think my tuner may have tuned around this or with a failing sensor...lets see...

 

ahhh... im so glad someone brought this up. i was having the same thing happen.

 

Don't listen to that Drop Dead Fred dude he spews nothing but guesses and thinks he knows everything all over the forum it's actually quite annoying.

Had the same issue on MAF sometimes and pump and pressure were not the issue whatsoever. Fuel Pressure remained fine and a new 255 made no difference