Exhaust conversion failure....

[MatteMan]

Hello

Had the car for inspection taday her in Sweden, and tha exhaust conversion was wrong (too high). Can it be the HO2S thats broken, or maybe the catalytic converter ??
Or can it be something else?

Have one more question, how do you know if you have 2V or 4V ?

Thanks, Mattias

 

[Torinalth]

you have a GT, so its going to be a 2v, only the cobra and the Mach1 are 4 valve.

if the exhaust conversion was too high it sounds like probably the cats are worn, though on an 01 i have a hard time believing that this is the case. someone else with better exhaust knowledge will chime in im sure.

Torinalth

 

[Mike97gt]

ok is your check engine light on? do you have the stock cats? if light is on any codes? what type of test did they do?omthing in under the dash or did they put it on a dyno. get me this info and i can help

 

[MatteMan]

Okej the cats maybe... quite expensive right?
Whats the price for a stock one?

 

[MatteMan]

ok is your check engine light on? do you have the stock cats? if light is on any codes? what type of test did they do?omthing in under the dash or did they put it on a dyno. get me this info and i can help

No the check engine is not lighting. and I think it is the stock cats.

We do a inspection of the car her in Sweden evary year, and they check everything like brakes, tier, suspention, lights and exhaust discharge and so on.
So my value on the exhaust was to high.
Here is the resultat, but I don´t know if you have the same over ther. The numbers in the parenthesis is max.

CO: 0,7 (0,5)
CO 2500: 0,6 (0,3)
HC: 137 (100)
Lambda: 1,07 (1,03)

Lambda = HO2S in usa


Thanks, Mattias

 

[MatteMan]

Someone having an idea?

 

[Torinalth]

does the mustang have the stock exhaust? the numbers rae not really high enough to show a complete cat failure, though the car could be running rich enough to either overpower the cats ability or you could just have one dud. stock cats are pretty cheap, though if you are going that far you might want to think about getting a new midpipe with cats and get some more power while you are at it.

i really dont know much about the 02 sensors so i cant help there.

Torinalth

 

[MatteMan]

does the mustang have the stock exhaust? the numbers rae not really high enough to show a complete cat failure, though the car could be running rich enough to either overpower the cats ability or you could just have one dud. stock cats are pretty cheap, though if you are going that far you might want to think about getting a new midpipe with cats and get some more power while you are at it.

i really dont know much about the 02 sensors so i cant help there.

Torinalth

I have Flowmaster mufflers on it, other then that I think it is stock.
Maybe it is the O2 sensor then...

Thanks anyway!

 

[2001sleeper]

check the 02 sensors, that is more likely the issue than a catalytic converter

 

[MatteMan]

check the 02 sensors, that is more likely the issue than a catalytic converter

Okej! It´s two of them right?

 

[rickster99]

Okej! It´s two of them right?

Actually if I am correct I think there are four sensors.

 

[stangman16]

Actually if I am correct I think there are four sensors.

Yes! Absolutely correct, there are four of those buggers. 2 front and 2 rear O2 sensors.

 

[rickster99]

Yes! Absolutely correct, there are four of those buggers. 2 front and 2 rear O2 sensors.

Yea thats funny. I remember a year and half ago I bolted on the x pipes and I thought I remember seing and messing with four sensors.... although I wasnt sure completely. I have been working on my 1991 F-150 so much that I havent had a chance to work on the Mustang at all... just to wash it from time to time.

 

[MatteMan]

But is there not only two heated oxygen sensor (O2 sensor) and two catalyst monitor sensor (I think I have read something about that) But what are the catalyst monitor sensors doing?

 

[MatteMan]

Can it be the PCV valve that makes the high exhaust value?

 

[green_fow_six]

But is there not only two heated oxygen sensor (O2 sensor) and two catalyst monitor sensor (I think I have read something about that) But what are the catalyst monitor sensors doing?

If you change them out, just change the front. The rears do not affect your exahust readings since they are after cat, they are just monitors.

 

[Mike97gt]

WOAH this is spinning out of control . do not buy 02 sensors.. that is not your problem.

sounds to me like the cats are gone. you guys have too remember this car is running in sweden right? well swedish fuel is different and unless the car is tuned for swedish fuel then you could have problems like this.

replace the cats then look into a way too reprogramm the computer to swedish feul standards.

 

[MatteMan]

WOAH this is spinning out of control . do not buy 02 sensors.. that is not your problem.

sounds to me like the cats are gone. you guys have too remember this car is running in sweden right? well swedish fuel is different and unless the car is tuned for swedish fuel then you could have problems like this.

replace the cats then look into a way too reprogramm the computer to swedish feul standards.

hum... yes we are driving on 95-98 octan here in Sweden.

But the value is not so high, can it really be the cats? It sounds to me, if the cats a broke, the value should be higher?

We have many Mustangs here in Sweden and ther is no problem with them. I also owns a -94 GT mustang, the exhaust value is very good on that car, almost zero on the test result...

 

[MatteMan]

I have notice that I only have 2 cats H-pipe, can that be the reason why the exhaust value is to high?? it´s 4 of them original right?

Maby I can buy two universal catalytic converter and weld together on the H-pipe? would that work?

Thanks

 

[2k2fourpointsix]

There is an extended waranty on any emission related item including the cats, they should be replaced under warranty. However this could be a problem given you location. Definitly look for a custom tune adjusted to sweedish octane levels...