A mechanic replaced a 1997 850 engine with a 1994 without permission. He modified components to get it to fit in the 97 engine compartment. The car needed to pass the emissions test and it failed. Does anyone know what the differences are in the emissions systems between those two years? I know that the heads are different. The 94 engine runs beautifully. Can the emissions be brought in line with the 97?
I dont quite understand?
If the replacement engine bears the same engine code (i.e. 2.5 20v would be a B5254FS) then the original management system will run it in the later car and confirm to the emissions standard.
The engines did not change between years (internally or fuel system), and you would have no difficulties.
Tim..
How much was replaced, only the shortblock with head or also ECU etc. Is it replaced with the exact same type of engine?
The Volvo engines havent changed much if any these years, so shouldnt be a problem getting it running correct. Try reading the error codes to get an idea of where the problem is or say what part of the emission test it has failed on. Might only be some air leak, not unreasonable to think of if an engine transplant has been done.
Greetings Niels
Hi Folks....
How are emissions tested where you register the car?
Most jurisdictions test OBD II vehicles [1996 and newer] by plugging into the DLC and reading the readiness status of the car....active codes, pending codes and clear readiness monitors. Some, however, simply analyze exhaust gasses by means of a probe in the tailpipe.
Your 1997 model should fall into the former category...testing by electronic reading of the vehicle data systems. Is your MIL [check engine light] illuminated? Does it work when you turn on the ignition, then go out when the car starts and runs?
Previous commentators are correct in that there is no significant mechanical difference between a 94 and a 97 engine. So long as the management system is from a 97 then you should have no problem passing a smog test.
Let us know the outcome.
Best Regards
wharf rat las vegas, NV
In California as least what he did is a no-no. You can't take a vehicle backwards to an earlier model year engine and if they discover you have done so it flunks the smog test even if the emissions sniffer says aok.
There are lots of details which may well be different from the '94 to the '97.
Which is stupid IMO, I'm all for clean running cars, but if the sniffer says it's good, what excuse do they have for failing it?
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