Hi, my car is a 97 Talon NT. A few days ago my check engine light came on and I took it to a mechanic who read P0134 O2 Sensor Circuit, NO activity Detected ( bank 1 - Sensor 1). We cleared the code and the next day my check engine light came on again, I didn't get it read again because was sure it was O2 sensor. This whole time my car is hesitating when I give it gas and idles like shit, hesitation has been around for a while now but is getting a lot worse lately.

Today my CEL started flashing on way home. I just read about keydance and tried it out. Got 3 codes.

12-battery unhooked in last 50 days i guess, weird thing is that I don't believe it has been. Not by me and I am pretty sure the mechanic didn't unhook it.

43-Ignition coil #1 primary circuit

21-Injector #1 control circuit

I think this is weird considering that code 32 didn't come up which is supposedly equivalent to P0134. It makes me wonder what might actually be wrong. Anyone have any ideas on what to do? Could it possibly just be my O2 sensor malfunctioning?

12-battery unhooked in last 50 days i guess, weird thing is that I don't believe it has been. Not by me and I am pretty sure the mechanic didn't unhook it.

Everytime I take my car to my mechanic he ends up unhooking the battery.

As far as the code. To me it sounds like the car isn't reading the O2 sensor. Which would cause your a/f mixture to be messed up and in turn cause your car to hesitate.

It's not within the last 50 days, it's within the last 50 key cycles.

A flashing CEL is an active misfire in your cylinder. Do a search about a flashing CEL as I know this has been talked about very recently so you know what to look for.

Originally posted by murray1
Got 3 codes. 12-battery unhooked in last 50 days i guess, weird thing is that I don't believe it has been. Not by me and I am pretty sure the mechanic didn't unhook it. 43-Ignition coil #1 primary circuit 21-Injector #1 control circuit I think this is weird considering that code 32 didn't come up which is supposedly equivalent to P0134. It makes me wonder what might actually be wrong. Anyone have any ideas on what to do?

I don't know where you're reading your codes, but 32 is an EVAP or EGR code, 21 is an o2 sensor, and 43 is a misfire code.

Just thought I'd point that out.

I got my codes off of this site. Underneath is the actual link

http://www.2gnt.com/index.php?d=PCM_Error_Codes

So 21 is faulty oxygen sensor and 43 is misfire?
This is good if the case because I would guess would be just my o2 sensor. Having those wrong codes was making me wonder what was actually wrong.

Someone should update/fix that page or delete it as it is useless.

Ok, I am confused now. I went and bought an oxygen sensor and installed it in my car. It is a bosch 13399 and looks to be right and everything. After I finish installing it I unhook battery to clear codes, then I hook the battery back up and start her up and drive away.

I notice that the idle has improved a fair bit but still not smooth and the hesitation is not near as bad. Still when I accelerate my car does not just spring to life like it used to and you can hear the poor performance as well as the engine kind of makes a lumpy bluuuuuuuuhhhh sound when accelerating instead of a nice solid wheeeeaaahhhh like it used to, sry but that is the best way I can describe difference in sound.

Well anyways about 10 minutes later my CEL comes on and when I get home I do keydance and code 43 again. What could it possibly be?

Oh and by the way my mechanic never unhooked the battery. I don't know if plugging in code reader or clearing codes would cause code 12 but it sure makes me wonder. Does anyone have a link to the correct keydance codes/meanings?

I found a page with the keydance codes and meanings.

http://asog.net/content/view/23/25/

Our table here should be corrected if possible.

you probably fouled your plugs out from running so rich without a functional front 02 sensor. Check your plugs and wires and measure the reisistance of the coilpack with a dvom if the plugs and wires check out.

Originally posted by murray1
Our table here should be corrected if possible.

Our table isn't incorrect, you just aren't reading it the right way. You looked under the scan tool list. I'm assuming you don't have a MUT-II and that you actually did a keydance. In which case the correct column you should be looking under is the one that says "CEL".

Code 21 is equivilant to the PO134 and you do have a bad upstream O2 sensor. You did happen to get lucky on 43, that is your Ignition coil #1. Like already stated check your coilpack and wires.

Ok, yeah I totally misread the table. I had done a quick search and found a similar problem that they pointed to the table and I didn't read it good enough.

I have checked my plugs and they don't have signs of fouling or running rich. If anything they seem ok but I did notice one has a worn electrode so I am going to replace them tomorrow. Wires look good. How would I check the ignition coil? Is there a write up on that somewhere?

Originally posted by murray1
Someone should update/fix that page or delete it as it is useless.

No, you should learn to read. You're reading the scan tool column, not the CEL-blink column.

Thanks, that was already cleared up though.

Thanks for the help. It ends up it was just my plugs and o2 sensor. I bought my new plugs and a tool to gap them to 0.45 then after I installed them I checked gap on old plugs. I didn't have one less then 0.055 and the worn one was 0.08.

Just for future reference for you, Darkone has got the factory service manuals in his sig, maybe you should look to that next time you get in a bind. That is quite a useful tool and asset to you and this forum.

Hey thanks for pointing that out. I have looked for manuals online but this is first time actually came across it. Thanks darkone for also providing us with that information.

Originally posted by murray1
Hey thanks for pointing that out. I have looked for manuals online but this is first time actually came across it. Thanks darkone for also providing us with that information.

Welcome.

Ok so its only been a week or two and I noticed last couple days my idle has got a little lumpy again. Then today my check engine light comes back on and I do keydance and get code 43 again. What should I do? I changed spark plugs and front oxygen sensor before. I'll check my spark plugs but it shouldn't be them hopefully.

Did you check your coil pack?

Hey, I was gone for the weekend and family member took my car to a friend who is a mechanic. I guess that the one spark plug wire was no good under the boot. It was arcing against the spark plug or something. He replaced the spark plug wire and spark plug and it works good again. Thanks for the help.