My S80 has hard stored codes in ecm but my engine light is not on any more but scanner does show codes. Does the light go off after a long time on. key on light does work.

 

No - (unless it was a evap/gas cap code and now the gas cap is tight) and don't really understand what you are asking. What problem are you trying to solve?

 

its the dreaded catalytic converter codes for both cats.

 

OK - do you need no codes to be stored to be able to get a tag/registration ?

If not - ignore them. If so - and they are converter efficiency codes - have someone (illegally) install rear an o2 sensor extender, erase the codes, then hopefully get thru a drive cycle, and have a passing e test.

 

I get the codes after 3 startups and yes next year its due for emissions.I just had some miss fires on the way to work, will check if codes are still there for cats.

 

O2 sensor heaters are tested when first started. (that could simply be a fuse blown, due to a shorted PCV heater on some cars)

O2 operation and converter efficiency take 20 minutes or so under the best conditions to test and set a code if there is a problem.

Exactly what codes do you have?

 

well I checked for codes and the hard codes are all gone P0430 and P0420 all ways comes up

 

Those are cat efficiency codes. Do you need to pass an emission inspection to get a tag? If not ignore them.

If so, try rear o2 sensor extenders and have someone install them (illegally) to see if that will prevent the efficiency codes from returning.

Or - replace your cat and O2 sensors!

 

Piling on what hoonk said: Here's a good resource for learning more about the fault codes.

https://www.dtcdecode.com/Volvo/ECM-P043000

As noted, the root cause can be the cats (particularly if your car is consuming oil or coolant (say via a head gasket issue) which may have contaminated the converts, the O2 sensors or an air leak. For the air leaks, give a listen to see if you hear any exhaust sounds up front to see if you have an issue with the flex pipes/header/EGR tube etc (or have your shop inspect next time the car is in for service and up on a lift).

 

yes early next year for emission inspection, I had the cats replaced.with 250.000 miles I think motor is worn out.

 

I'd bet you purchased aftermarket cats, and they are worn out.

Aftermarket cats - the reason they cost ~1/5 of factory - they have ~1/5th (or less) the precious metals in them and maybe last 1/5 as long!

 

no I payed extra for good cats. they did no good for my problem. with stock cats or after market same problem.

 

who in the hell would spend 4.000 for cats.