I recently bought an Elantra 2001 model car. When i did the emmission
test, it failed with high CO and HC. CO percentage was in range 5-6.
Its fuel consumption is also very high.
The idle is very smooth, no knocking when accelerating and no other
unusual behavior either.
As the first thing, i replaced all spark plugs, got the distributor
checked and wires checked. They are all fine. Then i did a fuel system
clean and checked whether there are any problems with injectors and
they were fine too.
Today, i got its ECU scanned and it gave the code p0342. I replaced
the camshaft position sensor, but it still gives the same code. In
addition, the reading of oxygen sensor voltage is 0.0V always. When
inspected, we could not find any oxygen sensor! And the engine runs
always in open loop (even after it gets heated!). Now im fully
confused! Please let me know whether there are engines where you don't
have a oxygen sensor? And if there are engines like that, will they
run in open loop always?
thanks in advance!