p1123 and p1125

[djomlas]

i have a simple obd2 reader, came up w these two.
based on my booklet:
p1123- throttle positon sensor range but higher than expected
p1125- throttle position sensor intermittent

btw, its a 98 2.5 manual, only thing done to it engine wise was a Evo intake

anyone have any suggestions? any help is appreciated in helping me fix this

thx, DJ

[MNBoxster]

Hi,

It's the EVO...

Happy Motoring!... Jim'99

[blinkwatt]

Congrats,you just lost your MAF,send an email to Sunset,986online.com,Suncoast and see who wants to sell you the non egas for the lowest price. I had P1123/11125 almost 1.5 year ago,a dirty K & N was the culprit. I don't know if 986online will still do it but they sold me my MAF for $233 shipped. If you don't change it out you will soon be expierencing hesitation when you give it some gas and you will also get spiratic idling.

[Rodger]

The 98s are non-E-gas, so any throttle position error should be direclty attributed to a failure of the potentiometer itself. In fact, one of things a lot of Porsche dealer "say" they do is check the smoothness of the throttle during routine service.

If you've got real-time feeback capability of the throttle circuit, you should be able to turn the key to ON (without starting the engine), and slowly push the pedal down. As the throttle opens, you should see a corrosponding smooth change in displayed voltage. I think the throttle operates from .5 to 4.5 volts. If there are any large fluctutations in voltage or the voltage doesn't increase smoothly, the throttle sensor is going bad.

If it's the MAF, try cleaning it first.

[djomlas]

i tried cleaning it with electric contact cleaner like some people on renntech suggested, but no luck.

evo says that there should be no CEL occuring when installed

also, whats the best way to see if its the MAF or if its something else?

[NickCats]

Originally Posted by MNBoxster

Hi,

It's the EVO...

Happy Motoring!... Jim'99

Jim,

Why do you think the EVO would throw up codes related to throttle position ?

Just wondering...

Thanks,

Nick

[djomlas]

it could and it couldnt.
from my research b4 the purchase, no one reported one, so im not sure yet if its the intake or jsut that it happen to go bad after i put the intake.
i cleaned up the MAF w contact electrical cleaner, reset the code, and CEL went off, didnt come on yet, so i will report back

[MNBoxster]

Originally Posted by NickCats

Jim,

Why do you think the EVO would throw up codes related to throttle position ?

Just wondering...

Thanks,

Nick

Hi,

@ Nick - There are lots of components which do not have their own CEL. For instance take a MAF - there is no OBDII or 'P' code which states "Bad MAF". This is because the sensor either isn't self-diagnosing, or for reasons of cost, memory space, or complicated code, the DME doesn't monitor the sensor's specific condition.

Consequently, many of the CELs report a variance to known or expected voltages or conditions. Therefore, you often need to do a little detective work figuring out which components affect such conditions and using experience (we all know how susceptible the MAF is to any screwing around), intuition and deduction, zero-in on the offending component, such as in this instance.

I say it was the Evo because when it was swapped, I suspect that it either jarred the MAF into failing, or let loose some dirt from the intake tubing and set off the MAF. A MAF malfunction could manifest itself into a condition resembling a throttle body issue - Revs not matching TPS (Throttle Position Sensor), or O² Sensor data not matching expected Data (too rich/lean), etc.

This is why it isn't that unusual to see CELs when people add or disturb components which were otherwise working fine (or at least within acceptable tolerances).

I deduced that since dj reported the EVO swap, this was complicit in the issue. If he hadn't added the EVO, I suspect the car would have never thrown the code (of course, this is speculating)...

Happy Motoring!... Jim'99

[djomlas]

true that Jim,
maybe if i didnt touch anything it wouldnt throw a code, but maybe it would, i guess well never know.
today i put over 50 miles on the car and no code but when i got home i got a CEL, i was like sht i jinxed it.
it turns out that when i gased up i didnt close the gas cap all the way, phew
it was a p0466 code

[blinkwatt]

Originally Posted by djomlas

it turns out that when i gased up i didnt close the gas cap all the way, phew
it was a p0466 code

I'm gonna remember that for future reference. Good info!

[djomlas]

well there could be a few other things, but that should be the 1st to check out since its free and easy to check

[NickCats]

Originally Posted by MNBoxster

Hi,

@ Nick - There are lots of components which do not have their own CEL. For instance take a MAF - there is no OBDII or 'P' code which states "Bad MAF". This is because the sensor either isn't self-diagnosing, or for reasons of cost, memory space, or complicated code, the DME doesn't monitor the sensor's specific condition.

Consequently, many of the CELs report a variance to known or expected voltages or conditions. Therefore, you often need to do a little detective work figuring out which components affect such conditions and using experience (we all know how susceptible the MAF is to any screwing around), intuition and deduction, zero-in on the offending component, such as in this instance.

I say it was the Evo because when it was swapped, I suspect that it either jarred the MAF into failing, or let loose some dirt from the intake tubing and set off the MAF. A MAF malfunction could manifest itself into a condition resembling a throttle body issue - Revs not matching TPS (Throttle Position Sensor), or O² Sensor data not matching expected Data (too rich/lean), etc.

This is why it isn't that unusual to see CELs when people add or disturb components which were otherwise working fine (or at least within acceptable tolerances).

I deduced that since dj reported the EVO swap, this was complicit in the issue. If he hadn't added the EVO, I suspect the car would have never thrown the code (of course, this is speculating)...

Happy Motoring!... Jim'99

Thanks, Jim !

Nick