Engine light - P0120 code - having no luck fixing it :(

[Meek_racing]

I've had an error code P0120 with the engine light and squiggly line one above oil temp. Fred cleared these last week and the engine ran perfect on the way home.

The next day I come to drive it and it's back in limp mode and both lights come on again. The car is sluggish but throttle response is fine, it wont go above 3k revs and I feel like a penis limited to 40-50mph driving on the motorway lol.

This morning I checked the code at a local garage and it reads P0120, I've replaced both throttle body and pedal from my gf's 182 and still having the same issue The engine light has gone off for now but the squiggly one comes on when you go into drive. On start-up and tick over it has no problem, but as soon as you engage drive and pull away, it comes on...

Help please

 

[Bluebeard]

Have you googled the code?

 

[Meek_racing]

I've done a few searches and they come up with a whole host of issues for the TB and pedal sensor. Mine doesn't seem to match any as I can drive it fine and no issues with idle speed etc. From what I've read it could be wiring, ECU, or another sensor throwing the fault. Just need advice what to do next as I could end up throwing a lot of money into parts that aren't needed.

 

[Meek_racing]

I've also tried swapping the coil pack from the gf's car but no luck.

 

[rollerdan]

Dont know if its any help but i had the same symptoms as you and it was a faulty injector mate .

 

[iOllieSM]

I have these same issues with Mine and its driving me absolutely nuts. It usually only seems to do it when it's wet weather. Can't seem to get rid of this issue. It comes and goes, like il clean up a load of stuff and it'll run great for a week, 2 weeks, sometimes months then it'll come back again! If you do fix this let me know what it is please
Ollie

 

[TheEvilGiraffe]

One nanosecond on Google = P0120

Throttle Pedal Position Sensor/Switch A Circuit Malfunction

So, check / clean / replace that.

Clear the code, if it re-occurs, set fire to the car and buy a new one.

 

[Meek_racing]

I've swapped over injectors and still the same issue

 

[bmh.01]

Why are you swapping things completely unrelated to the fault???

Its either the throttle body, pedal or loom. Going on Clip for some more detailed information wouldn't hurt either.

 

[Meek_racing]

I replaced both pedal and TB with no luck, Dan mentioned that he had the same issue but it turned out to be the injectors... so it's only natural to try that is it not?

How does a clip differ from a standard garage diagnostic? The only error code it reads is P0120. I've been chatting to Mick about this so might have to take it there for a good look.

Why are you swapping things completely unrelated to the fault???

Its either the throttle body, pedal or loom. Going on Clip for some more detailed information wouldn't hurt either.

 

[Tony Hunter]

Its a difficult one, has been known to be fuel pump or sender, this doesn't show it's own code, but chucks out another one unrelated.

 

[Meek_racing]

That's what Fred told me, just need to corner him into doing something As above, Mick has offered to look at the car when he's back off holiday.

 

[Tony Hunter]

Me and Fred agree, again.!

 

[Meek_racing]

I thought I would update this in case anyone else has a similar issue.

Poor running and limp mode was due to pre car lambda sensor. There was also moisture in the main bulkhead connector to ECU.

Slow speed grinding was due to the ABS ring being cracked and causing the ABS to kick in when coming to a stop.

The car surging when at constant speed or slowing down was due to the rear caliper binding to the extent that the rear disc had cracked!

All parts replaced and works like new