Sho Misfire

[mechsho]

I have a misfire in my 92 mtx and cant fix it.I pulled the codes KOER 172 ego not switching lean bank 1,and 159 mass air flow voltage out of range.Wil this cause a misfire?

 

[jkichline]

I have a misfire in my 92 mtx and cant fix it.I pulled the codes KOER 172 ego not switching lean bank 1,and 159 mass air flow voltage out of range.Wil this cause a misfire?

yes, either one of those can cause a misfire. Make sure your maf sensor is connected. If it is, make sure its clean. If not, clean it up real good with electronics cleaner. If that doesn't work, your MAF sensor may be shot.
You probably need a front O2 sensor. If you replace one, you might as well replace them both. Make sure you use the right size wrench. You'll have to use some PB blaster on the threads. The easiest was it to spray the PB blaster once or twice a day for a few days then attempt to take it out. The loosen MUCH easier when the exhaust is hot. I usually heat the pipes and, VERY CAREFULLY, torque as hard as I can to get them loose. Once their loose, let the exhaust cool off for an hour or so and take them all the way out. Put the new ones in but use some anti-seize on the threads.

 

[wood_e]

Is there oil in your plug wells?

 

[mechsho]

No oil in the plug wells!! But when i pull the MAF connect i have no engine change it runs the same with or without MAF plugged in.

 

[FoeSho]

I woudl say thats a Bad Maf then.

 

[mechsho]

Well i would to but!......I have already replaced MAF . Now ther is some after market MAF plug on it that never gave me a problem before,does anyone else have this plug.It looks like the 4 wires were cut and rewired with new color coded wires.

 

[mylaw]

I am having the same issue .. I replaced 02 sensors and new plugs I am now replacing my MAF and my wires that should correct the problem !!!

 

[sdpatt]

I'll say it again, a misfire without any telltale engine control system codes will be the plugs and/or plug wires 99% of the time.

 

[mechsho]

sorry bro , i put brand new plugs and wires twice just to make sure it was'nt that.All motorcraft wires and plugs.I'm getting 14.23 volts to the power wire on the MAF,i don't know what should be coming out of the reference wire from the MAF mabey thats my problem.

 

[mechsho]

And i tried a new coil and DIS

 

[mylaw]

Does it happen when car is hot ! I found my problem by removing each wire from the coil wire running... One at a time .. Make sure the coil is sparking for each wire properly...Could only be a couple of things that cause that ! maybe even timing...

 

[mechsho]

i have spark on each wire

 

[mylaw]

does the idle drop when you remove each wire one at a time
It should !

 

[mechsho]

Yes is'nt that funny.Thats why i think its MAF

 

[jkichline]

Have you tried cleaning the maf with electronics cleaner?

 

[mylaw]

It is not the MAF I just replaced my MAF and found out that the idle is supposed to drop I have it where one wire does not do anythiung I would check catalic converter or ECU !

 

[mylaw]

Sorry It can be the MAF I did not notice you had codes
Replace MAF and good to go

 

[mechsho]

It's fixed!!!!(New MAF) and a full injection cleaning cleared the misfire right up!!!WoW cant believe it.Thank you to all that helped on this one:0)Its been 6 months since i have driven this car its crazy.Now this car hauls!!(92 MTX with a 91 motor with 65k on it.All the hard work just paid off!!!!