AdrenalineRush

iTrader: (4)

I'll make it as short as possible. I REALLY need help with this. Car is my DD and is at a friend's shop 30 mins form my house so at the moment and screwed

-Last week started car up. Wideband was reading (---) all the way to work. Very hard to accel. Threw a P0134 code (O2 non responsive) on way to work
-Got in car after work. Car ran "fine" was idling in the 10s-12s just depended
-Reset code, car ran fine. AFRs were normal.

Next Day

-Started car and the exhaust note was "doubling" up. Car was idling and running very rough and when cruising the wideband was going from 12s to (---) and back again. But was still able to drive with little issue. Though may the wideband was reading inaccurate
-Went to AdvanceAutoParts and bought a Denso O2 sensor (Part # 234-4741) cause I read this was the OEM replacement.
-Swapped it out car is running WAY WORSE!! Not sure if the sensor is bad but at even idle now afrs go from 12s to (---) and back again over and over. Def not getting fuel and the P0134 code came back up after the swap. WHen trying to cruise the car will go full lean and enter limp mode, then will go back to 12s-18s over and over still going to full lean not letting me really step on the gas at all.


Below are some logs I took. Oddly on idle the car was in the 12s but still idled consistent based on the wideband reading. Went cruising and while running rich was staying consistent. HERE ARE WHERE THINGS GET WEIRD. Everytime I've let the car sit for awhile it starts fine and idles fine BUT when I did a pull to log after the initial warm up things went to complete **** :/ Started idling near 12s again all the way to (---) and over and over again almost stalling over and over as you will see in the LAST log. The last log I turned O2 sensor feedback and and that **** is all over the place


PLEASE HELP I'm at a loss for words besides maybe the new O2 I got being bad, injector maybe being clogged (dont think so), etc. Maybe I need to order the Walker sensor and try again?

Thank you!

Alex Stillwell

AdrenalineRush

iTrader: (4)

Bump anyone?

Fast_Freddie

iTrader: (50)

Have you cleaned the MAF? Try that with the CRC Mass Air Flow Sensor Cleaner mang... Also check for possible vacuum/boost leaks as well...

misterevo8

hmmm, MAF, Fuel pump going out, fuel pressure regulator? ans what the guy ^^ said, boost/vacuum leaks?

Xplosiv

Just for my own understanding, you replaced the o2 sensor for your wideband with a denso oem replacement? Dont the wideband o2 gauges use their own specific o2 sensor?

AdrenalineRush

iTrader: (4)

Read sig. Speed Density no MAF. I will be doing a boost leak test in about 3 hours.

After I do the boost leak test I'm gonna try and test the fuel pressure regulator that is what I've been told may be the problem if I don't have any leaks found after the boost leak test.

No the OEM O2 sensor was replaced with the OEM compatible Denso O2 sensor. I have a AEM wideband sensor sitting at the ready but obviously with the way the car is running I do not believe the AEM sensor to be faulty.




Working on uploading a shorty clip of what the AEM Wideband is reading. Its short because it just cycles from 12s-(---) and over again the the rpms do fall a bit when the car goes very lean so I know it is not the AEM sensor

AdrenalineRush

iTrader: (4)

Video: it's been worse than this too as AFRs drop lower while driving and gets leaner for longer periods of time and I enter limp mode and had to pull and crawl back to friends shop

http://i688.photobucket.com/albums/v...2D97B83933.mp4

blowngasket

iTrader: (4)

Is it still throwing codes? I start checking wirering if so. I had a issue with mine at that Damn firewall boot, the previous owner cut the wire somehow [prolly when running the boost gauge line] And just taped the damn wire! it was all corroded up, i had a hell of a time fixing that. But luckly i found it.

Mine was doing the same thing EXACTLY, but very sporatic

AdrenalineRush

iTrader: (4)

Any specific wiring? Car has new plus and SpoolinUp COP that was added just 6 months ago. Based on the logs the spark was acting normal at least from what I've read/seen

blowngasket

iTrader: (4)

Just take a look at that boot to firewall, its behind the alternator on the passanger side of the firewall. Make sures its intact no hacks or obvious electrical tape sticking out. Mine had a frayed Red wire and Green with a white stripe wire. After i repaired it all was good. I never tracked down what they wires were thou, BUT it solved my issue 100% i was at 14.7 it would randomly Go lean at idle, other wise driving was fine.
It goes thru the passanger side, so you can see it under the dash thru the passanger side too.

TommiM

iTrader: (19)

Is it possible to have the wrong O2 sensor? IIRC, the downstream sensor has two different part numbers depending on if you have an 03 or a 05 later, or something like that. Sounds like you replaced the upstream one from what you wrote and if memory serves me right those are the same for all evo 8 and 9.

Could also be a bad sensor from the parts store. I have personally seen the guys at the parts stores unloading the truck when Ive been there at night. Full boxes full of sensors and spark plugs, and they slam it down on the ground next to aisle they are supposed to be put away in. Im sure that cant be good for them.

Xplosiv

Not only that, but sometimes parts are bad from the manufacturer. Also ive ALWAYS had better luck with OEM o2 sensors vs oem replacements. I know they are more exspensive but your o2's are something you really dont want to mess with.

matrho2792

iTrader: (30)

Also had a very bad experience with part store O2's. I went through 3 in one year in my 2008 Eclipse. It had the same symptoms your Evo has. I replaced it with an OEM and all the problems were solved. I would take it back and get your money back.

RSGuy

iTrader: (12)

Make sure your ecu/o2 wires are good. If you plug a scan tool in, do you get a reading for o2#1?

STLEVOIX

iTrader: (17)

I think he got this fixed. He had a bad leak at the coupler to TB. He should chime in.