Brand new o2 sensors code 172/176

[mrgrim333]

Trying to get my sho to pass emissions.
Even with spout pulled, still .5 too high on HCs.
Replaced the plugs, and the o2's today.

First her up, romp the **** out of her around the block a few times.
CEL codes 172/176, both are fault/lean error.
(Had a 528, clutch circuit fault, but Ef' that for now)

Reading around, everyone keeps saying it's rare to have both go bad at the same time, let alone, brand new, right out of the box oxygen sensors.

Someone suggested it could be the fuel pump? I'm thinking maybe that's where my problem really lies? Considering I used to get 556 (Fuel pump circuit failure) intermittently since I've owned the car.

 

[Fordlover96]

Vacuum leak? And if the pump is starving the engine of fuel, it will defiantly run lean.

 

[mrgrim333]

Now my issue has evolved to this.
All because of new sparkplugs and o2s.
Slow rev to 5k rpm I have bucking and loss.
Rough idle at stop signs (doing the volly then potentially dying thing).
152 (Maf sensor low voltage), 172/176, 212?
Maybe it's just a bad ground somewhere? I'm kinda at a loss.
Because to combat the 152 I bought a brand new MAF. Still throws the code.

 

[rubydist]

my regular code list does not show 152, so I searched 7 other sources for codes and none of them show a 152 for a Ford eec-iv...

From your description, you have a lean condition. high HC in my experience on the SHO are most likely due to cam being out of time. I had one car that would not pass emissions until I pulled the spout connector - it turned out the rear cam was 2 teeth off. (In other words, it doesn't have to be off much to completely screw up emissions.) and it had low power at the same time. You can also get high HC just due to too lean, in which case you either have a serious vacuum leak(s) or you have a sick tps. I personally lean toward the tps given your description of symptoms.

I would turn the crank pulley to 0* and pull the top timing belt cover to see if the cam sprocket marks are aligned with the marks on the steel top cover to make sure the cam timing is correct. If not, fix. If cam timing is fine, I would replace the tps.

 

[mrgrim333]

Well, I think I just have to give up some time after work for the next week and drive another car because I know now what has to be done.

I already have all the stuff to do my lower 60k, just been putting it off.
Just going with a whole new belt, CPS and I'll pick up a TPS too.

The fact that you mentioned the teeth being off made me realize where all my "performance" issues came from. Replacing the plugs, I accidentally left one of the wires disconnected before I ran it for a sec. Bet you my goof-up is what through the timing off. Curses! You make an excellent detective good sir. Positive now that my o2s are working just fine, but now my timing is off so it's reading lean, which is correct.

Anyhoo, lower 60k, here I come!

 

[kevinspann]

Leaving a wire off accidentally won't do anything to the timing...

Pull the upper cover off and see if the marks line up. It still sounds like a vacuum leak.

 

[rubydist]

well, if you changed the plugs, make sure you have the wires back on the correct locations - several of the books list the wrong wiring diagram - use the one from this site.

 

[mrgrim333]

The wires are in the correct location. My car ran perfect before all of this. All I did was replace the sparkplugs, front 3 a week ago, then, the back 3,let the back center wire out for a 20 second idle. Plugged it back in. Replaced the o2s without any issue. The only vacuum thing humanly possible is I pulled off my cross over tube in the top left of the engine to spray it out with seafoam. I took off the DIS sensor that sits on the side of it, reattached it and had no problems plugging it back in. Maybe I didn't seat the tube well enough? I can't hear a leak?

 

[rubydist]

when you reattached the dis, did you use heat sink paste under it? the dis will fry itself without that and you get all kinds of strange symptoms as the dis is in the process of getting killed. also, make sure that crossover tube is grounded properly or the dis will not function properly.

 

[95GOOSE]

Now my issue has evolved to this.
All because of new sparkplugs and o2s.
Slow rev to 5k rpm I have bucking and loss.
Rough idle at stop signs (doing the volly then potentially dying thing).
152 (Maf sensor low voltage), 172/176, 212?
Maybe it's just a bad ground somewhere? I'm kinda at a loss.
Because to combat the 152 I bought a brand new MAF. Still throws the code.

I pulled the codes on my 95MTX using the paperclip method, and also got a "152". As rubydist says in post #4, 152 is not listed. Did you use a scanner or jumper? Did you retest and get the same results?
Just curious.

 

[mrgrim333]

I used a scanner, but the paperclip method is exactly the same. I rid myself of the 154 by reseating my crossover tube. That MAF error is from a vacuum leak. Still having the o2 issue, only at 4k or higher that trips it. Too lean. Fuel pump?