CEL, O2 sensors not switching

chris2523

chris2523

93 Mark VIII
Joined
Nov 8, 2007
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Location
Central MO
i have the codes

172 (R,M) Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control

176 (M) Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control

336 (O,R,M) PFE sensor signal is/was was high - ">PFE

CEL comes and goes. gas mileage is down. doesn't run too great all around.

the egr valve is working. i can apply vacuum and get a nice clunk, and the engine runs rough. the imrcs are shut. and i can't find any vacuum leaks.

why do i have a high PFE sensor signal? what does that mean? do pfe sensors usually go bad?

if it was up to me, i wouldn't have any of this egr stuff.
 
Chris, do you still have your old computer? If so, I would try swapping it back in and see what you have. This could be a chip issue but most likely not. It's a free elimination check either way and it might end up telling you what you need to know.

Are you sure you don't mean the DPFE voltage is high?
 
NoLimit95 said:
Chris, do you still have your old computer? If so, I would try swapping it back in and see what you have. This could be a chip issue but most likely not. It's a free elimination check either way and it might end up telling you what you need to know.
Click to expand...


it isn't the chip. same codes with and without my chip.

but i'll try the computer swap. easy enough.


NoLimit95 said:
Are you sure you don't mean the DPFE voltage is high?
Click to expand...

yes. i'm pretty sure that's what i mean.
 
This is probably what you're going to end up having to buy. Right at $70 but I can go out in the garage and look to see if I have one in the tool box. I sent one to Laser one time but mine was Gen 1 and he was trying to put it on a gen 2. Kinda hard to get to but it is doable. Rockauto BTW

PartImage.jpg
 
i swapped the computer and drove around the block. no codes yet.

and yeah, i've got one of those ordered. should be here tomorrow.
i already have the hood off and wipers removed. it'll will be easy when it gets here.
 
It's good you have one ordered because I don't have one like I thought. The part I have in the toolbox was the EDIS from the 93. Laser got the other DPFE I had. It was a few years back so I couldn't remember if I had it or not. You can take the chip you have and put it in the DZA1 and it will then be identical to the W3Z2 you have the chip in. None of the good stuff about the Z2 matters anymore when a chip is installed.
 
Does the Z2 work on a gen 2 or just on gen 1 , ??
Found one in a yard , build date on the car was late 92
But my car is a 97 , just curious.
 
Hmmm , might have to grab it , depending on how much the dude wants to charge me for it, think it had a drive shaft too.
 
so i finally got the old codes cleared and the computer reset.
111. no codes. cool.
the egr ford gave me was the wrong one. so tomorrow they are trading it for the correct one. in the mean time, took it all apart, cleaned out the hoses, reset the computer, and drove around. no codes. wish the idle was higher though.

now, when the chip is in, i dont get a cel, but i do get a 511.

511 (O) No power to PCM pin 1 or bad PCM (processor)

this related to the chip? normal? goes away when i take it out...
edit: 511 seems very common with a chipped computer.
 
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Not sure about this one Chris. Have you put it in the DZA1 to see what happens? If it's common and you can actually feel the tune is still aggressive, I wouldn't let it bother me but I would rather have the chip in the DZA1 so that you would have the Z2 on standby with the more aggressive tune than the DZA1, just in case the chip does end up giving you problems in the future.

511 would almost have to be chip related but I'm just guessing.
 
i have a w3z3. i have ran both my z3 and z2 (no chip) some 20-30 miles each and gotten no new codes after a quick cleaning.
z2 and chip are back in, only 10 miles or so, but no codes.
 
chris2523 said:
i have a w3z3. i have ran both my z3 and z2 (no chip) some 20-30 miles each and gotten no new codes after a quick cleaning.
z2 and chip are back in, only 10 miles or so, but no codes.
Click to expand...

Hell, maybe the cleaning was all it needed. That would be nice. Get the money back on the other part, if possible. Don't fix it if it ain't broke.
 
true. but since i have it all apart already... and i don't want the issue to come back right after i return it.
i've seen this code before, and i bet it comes back sooner or later.
 
I kept saying you had a DZA1 because for some reason, I thought you had a 95 :rolleyes:.. Now I know why you kept saying W3Z3 and now you know why I kept saying DZA1 lol. Anyway, hope the problem goes away for you after the part is installed. Now I understand why you said you couldn't feel any difference between the two ECU's. The Z3 and Z2 are very close and both aggressive but not enough for the driver to notice. The difference really only shows on the computer when it's brought up to show the spark, timing etc..

Now, take a 95 DZA1 and put in a Z2 and you will feel the difference. 94 Z4H0, maybe a little difference but not a whole lot. I have had the 93, 94 and 95 and I would say the 95 benefits most from getting the Z2 installed.
 
went to the (closed) ford parts department and my guy there went in, dug through the shipping boxes, pulled my parts, called the guy who ordered it to make sure he had the right one, and brought it out to me. :eek: nice! :cool:

so its installed, and all back together. had to splice in a new wiring harness, but that's no issue. so far, so good. no issues.

side note..
turbocharged audi tt convertibles... pretty even with my car from 20-70. dunno what was done to it but it sounded sweet, a little whistle and then a whoosh when he let off to shift. blow off valve i guess.
 
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