'98 S70 - flash code 122, air temp sensor

[Stu70]

I'm hoping some body can help with this problem!
Fenix management 10v engine.
Air intake sensor
Returning 15 mpg city driving and smells like it's running rich.
I have replaced the sensor, traced wiring back to ecu all present and correct, 5v present at sensor.
Any thoughts on where I can look?
I have replaced the pcv system, and deleted the factory CNG ( one of 3 made, as press release cars) could this have an effect? I'm getting really frustrated, there is no CEL but I know it's there lurking...

[Stu70]

Any thoughts anyone ??

[crlande]

My 98 S70 uses the OBDII. P0122 which is the throttle position sensor.

https://www.obd-codes.com/p0122

[misha]

U.S market never got 10v cars,they are more present in U.K.(http://www.volvoforums.org.uk) and EU generally.

You can have few problems going on on 10v car:
-vacuum leak(almost always on any car)
-bad or slow o2 sensor
-map sensor or it's vacuum line
-ect sensor or thermostat
If i understand correctly,you have just a code for IAT sensor?
Does the car actually running rich...ie black smoke from the exhaust?

Since you have been in intake area recently for PCV replacement AND you deleted CNG system... i would say that you need to check intake manifold gasket and generally the whole area for some vacuum leak or some hoses disconnected.

Does the code appeared AFTER pcv system service or it was present before?

One more thing...
Factory CNG/TNG system is sequential system and their injectors are installed onto intake manifold,just after fuel injectors.
That said....what happened with the holes onto intake manifold where CNG injectors were?
If that is left unsealed,that's your problem.

[misha]

My 98 S70 uses the OBDII. P0122 which is the throttle position sensor.

https://www.obd-codes.com/p0122

It's 10v car with Siemens Fenix management and it produce flash codes,just like Motronic 4.3.

[Stu70]

Thanks for the help there Misha !
I sealed the injector holes with bolts and thread lock/sealer - I even went as far as contouring the ends of them that protruded into the manifold.
I must build a smoker to sniff out any vacuum leaks, looking back in my workshop part/repair journal; the fault occurred before the pcv job and CNG delete. It just smells like it's running rich - thinking now it's not linked- might check the canister...
Ive come to a dead end on the UK site, so yours is the first reply to this problem on any site
There is not an over abundance of these P80 cars in New Zealand, so parts are a week away from the US or U.K. and expensive , it's difficult to try substitute parts as there is only two being parted out in the whole country, so any help is always welcome !

[misha]

Ok,so you had a problem even before pcv system replacement and CNG delete?
Did the car smell rich before all of that or after repairs?
Did you drove the car periodically on petrol while CNG was in it?

I would say that petrol injectors would need professional cleaning because of driving the car on CNG.
Maybe they are a bit clogged and that's why you smell rich running condition.
What is the brand of IAT sensor you installed?

[Stu70]

Fuel usage has been high since before I undertook any work, I use a fuel tracker app , I don't have the trip computer.
CNG tank was removed before car was imported into the country, but its first 14 years in the U.K. it would have definitely been driven on both fuels.
Can't say exactly when it started smelling rich, but an injector clean sounds like a sensible job.
IAT was from dealer, so OEM. Being a 10v not many to be had from US or U.K. websites.

[scot850]

Are you sure the car is running rich and there is not a fuel leak near the back of the vehicle. Now that should through a code I believe but thought we may need to widen the possible cause issues.

Neil.

[misha]

Neil....raw fuel smell is totally different from smell when car runs rich.
So.... that can't be comparable.