codes

[95mustang_gt]

Well i bought a code reader from wal-mart for $30 and did the koeo and koer and these are the codes it give me 172,181,189,543.

Now in the owner's manuel this is what the codes meant

172-HEGO(HO2S) sensor fault/lean
181-fuel system at rich adaptive limit at partial throttle/system lean
189-fuel system at rich adaptive limit at partial throotlr/system lean
543-fuel pump secondary circuit fault

Are those right?I think i know what they all mean, but i just want to make sure that im right,so if someone dont mind explaing what they all mean, i will be very greatful.

 

[CManT1914]

Well i bought a code reader from wal-mart for $30 and did the koeo and koer and these are the codes it give me 172,181,189,543.

Now in the owner's manuel this is what the codes meant

172-HEGO(HO2S) sensor fault/lean
181-fuel system at rich adaptive limit at partial throttle/system lean
189-fuel system at rich adaptive limit at partial throotlr/system lean
543-fuel pump secondary circuit fault

Are those right?I think i know what they all mean, but i just want to make sure that im right,so if someone dont mind explaing what they all mean, i will be very greatful.

Sounds like your O2 sensors are bad. Does the car run bad at partial throttle? See I had codes 181 and 189, meaning that the computer is getting a bad reading from somewhere (mine was my MAF) and is dumping as much fuel as it can into the system, but still reading lean. With code 172, it looks like it's your O2's. A quick test you can do, is run the car at WOT and see if it runs like it should, cus the O2's are ignored anyway under WOT, meaning the computer doesnt take a reading from them, and instead calculates the A/F mixture according to a preset table. I don't really know much about code 543, hope this helps.

 

[91LX_5L]

do i need a code reader to read codes? I want to see if i can pick anything up

 

[final5-0]

Well i bought a code reader from wal-mart for $30 and did the koeo and koer and these are the codes it give me 172,181,189,543.

Now in the owner's manuel this is what the codes meant

172-HEGO(HO2S) sensor fault/lean
181-fuel system at rich adaptive limit at partial throttle/system lean
189-fuel system at rich adaptive limit at partial throotlr/system lean
543-fuel pump secondary circuit fault

Are those right?I think i know what they all mean, but i just want to make sure that im right,so if someone dont mind explaing what they all mean, i will be very greatful.

I wanna make it clear that I'm not sure but to me it seems like.............

the 181 & 189 code is saying the pcm has gone to the limit of its adaptive ability to the rich side trying to correct a lean problem. Also notice how the words "part throttle" were used which COULD mean close loop and the O2 sensors are used in cl conditions.

I wonder if the 172 code is for just the lert or right O2 or both O2's?

I don't have any idea about the 543 code.

Does the book that came with your code scanner have a help section?

Later
Grady

 

[bimmertech]

you should check for unmetered air leaks or air leaks before your o2 sensor. if the codes came on after you installed your l/t headers it may be the o2 sensor location, but i dont hear too much of a problem with that with 94/95, just foxes with unheated o2s. exhaust leaks before o2s can also make the puter think your car is lean. is it pinging, or running like dung?

 

[CManT1914]

do i need a code reader to read codes? I want to see if i can pick anything up

No, you can make your own "scanner" with a paper clip or something, I'll see if I can find the article.

 

[91LX_5L]

sweet thanks

 

[95mustang_gt]

Will running my car without cats cause any of these problems?Im sure the 172 code meant just 1 because 173 is another O2 code,but it doesnt say if its the left or right,i think i will just replace both of them.

To me the car seems to be running fine,i never hear anything that sounds wrong.

how can i check check for unmetered air leaks or air leaks?

SO what will i have to do to be able to fix the 181 and 189 code.im still a little confuse of the problem.

thanks everyone for helping out so far.

 

[bimmertech]

take some brake clean and spray it around all vacuum hoses and intake manifolds and listen for any changes in idle which indicates an air leak after the maf sensor which makes it umetered. as for exhaust leaks, you won't hear those until you have a load on the engine and gets louder the more throttle you give it. this is probably not the problem, but it is the first things you should check when diagnosing any sort of driveability issue.

 

[95mustang_gt]

so i will just spray the break clean on the vacuum hoses and the intake manifolds,i wont have to take anything apart?

 

[HISSIN50]

i dont know the code's number by heart, but the fuel pump secondary circuit generally means the FP lost power at some point since the KAM was last cleared. have you interrupted the circuit recently (tripped the inertia switch, etc)?

and i agree with Grady et al, about the code being that the system is lean (having tried to run as rich as it can to compensate).

a stockish fox will run at 15-20" hg of vac at warm idle (closer to 20 if healthy). i am not sure if changes were made to the SN's (cam, etc), so take that FWIW.

good luck.

 

[bimmertech]

don't take anything apart, just start the engine and let it idle at normal idle and spray it around the gasket for the upper/lower int gasket, lower/head gasket, t/b gasket, injector/lower o-rings, vac lines, etc.. another thing you can check if you still have it is your smog pump check valve, mine went bad and was allowing air pump to put air into exhaust when it wasn't supposed too.

 

[HISSIN50]

BTW, i think there is a link or info to retrieve codes with a paperclip in the FAQ at the top of the sub-forum page.

 

[mo_dingo]

1st test. Check your fuel pressure. Should be 39psi w/o vacuum....

Then check your vacuum with a vacuum gauge.......

post back when you do.
scott


edit: How to read codes w/o scanner
http://www.allfordmustangs.com/Detailed/445.shtml


Your O2 sensors are telling you that they can't add any more fuel, and you are running lean. You need to check the basics, like fuel pressure and vacuum.

181 is right side, part throttle, adaptive rich limit
189 is left side, open loop, adaptive rich limit
172 is the right side, telling you that side is lean

Scott

 

[yellowstang1994]

Can I ask you guys a really really really stupid question? Does your CEL light have to be flashing when the car is physically running to have codes on it? It just seems to good to be true that my car is in perfect working order *knock on wood*. But just a curious question. I have no CEL blinking. When I turn the igniton on the CEL light does come on, and it stays there. And I understand that all of the lights come on so you know if they work or not. But the rest of them go out, and the CEL one stays light, until I turn the car on. I didn't know if it was something ford did to let you know the vehicle needed servicing but they didn't want to bug the driver? I dunno let me know guys. I'm thinking about getting one anyway, just to see if my car is pulling any codes at all to be on the safe side.

 

[HISSIN50]

Can I ask you guys a really really really stupid question? Does your CEL light have to be flashing when the car is physically running to have codes on it? It just seems to good to be true that my car is in perfect working order *knock on wood*. But just a curious question. I have no CEL blinking. When I turn the igniton on the CEL light does come on, and it stays there. And I understand that all of the lights come on so you know if they work or not. But the rest of them go out, and the CEL one stays light, until I turn the car on. I didn't know if it was something ford did to let you know the vehicle needed servicing but they didn't want to bug the driver? I dunno let me know guys. I'm thinking about getting one anyway, just to see if my car is pulling any codes at all to be on the safe side.

the criteria to illuminate the CEL is greater than that to store a code. said another way, you can have codes stored without having the CEL lit up. if you have an intermittant issue that lights the CEL occasionally, even though the light is off at the present time, codes will remain in the KAM.
and even if your light never came on, codes can still be stored. in this case, chances are the codes are not something the puter deems as crucial, so the CEL is not lit up.

good luck.

 

[CManT1914]

Can I ask you guys a really really really stupid question? Does your CEL light have to be flashing when the car is physically running to have codes on it? It just seems to good to be true that my car is in perfect working order *knock on wood*. But just a curious question. I have no CEL blinking. When I turn the igniton on the CEL light does come on, and it stays there. And I understand that all of the lights come on so you know if they work or not. But the rest of them go out, and the CEL one stays light, until I turn the car on. I didn't know if it was something ford did to let you know the vehicle needed servicing but they didn't want to bug the driver? I dunno let me know guys. I'm thinking about getting one anyway, just to see if my car is pulling any codes at all to be on the safe side.

Just to add what HISSIN said, your CEL should come on when you turn the key, (as all the lights do) and it stays on until the engine is started. At this point it should go off unless you have a problem. But just because the CEL isn't on, doesn't mean that there aren't any codes stored. My CEL came on for a few seconds a couple months ago, then went off for a week. Then it came on for a few seconds a week later, then went off again. But this whole time I was throwing intermittent codes, meaning the problem wasn't constantly present. Make sense? Check out midwayautosupply.com, they have the code scanner for our cars for $33 or so. Plus it has the LCD screen (which actually displays what the code is) instead of the blinking light that you have to count how many times it flashes, those suck, lol. You might wanna pick up the extension cable for it too, that way you can pull codes while you're sitting in the car instead of having to walk back and forth.

Code scanner: http://www.midwayautosupply.com/detailedproductdescription.asp?3829

Extension cable: http://www.midwayautosupply.com/detailedproductdescription.asp?4077

 

[95mustang_gt]

1st test. Check your fuel pressure. Should be 39psi w/o vacuum....

Then check your vacuum with a vacuum gauge.......

post back when you do.
scott


edit: How to read codes w/o scanner
http://www.allfordmustangs.com/Detailed/445.shtml


Your O2 sensors are telling you that they can't add any more fuel, and you are running lean. You need to check the basics, like fuel pressure and vacuum.




181 is right side, part throttle, adaptive rich limit
189 is left side, open loop, adaptive rich limit
172 is the right side, telling you that side is lean

Scott

How much does the fuel pressure tool and the vacuum gauge cost?
bimmertech,where is the smog pump check valve located?

 

[bimmertech]

the check valve for the smog pump is on the pass side above the exh mainfold and should have a rubber hose going into it and out of it and a vacuum line on top of it. undo the hose on the back side(after the smog pump) and check for flow. now undo the vacuum hose on top and check it for flow and see if there is any difference. if there is a diif then its all right, if there isn't then you have a bad check valve and it is time to order that smog pump eliminator pulley and gut your air system.(its the cheaper, but non-pc way)

 

[mo_dingo]

How much does the fuel pressure tool and the vacuum gauge cost?
bimmertech,where is the smog pump check valve located?

Both are under $20 bucks.

I mounted a permenant fuel pressure gauge in place of the schrader valve (unscrew schrader valve, install gauge with adapter fitting, and you are done).

Summit sells the gauge and adapter fitting. Do a search and you find the right gauge and adapter fitting.

Get it from summitracing.com.

Vacuum gauge will hook up to any vacuum source on the car (vac tree near EGR valve is your best bet option).
Scott