Hey guys,

Im working on a 1999 Oldsmobile Alero 2.4L for a friend. It has failed emissions with a high NOx reading.

I was wondering if someone knows where the egr and pcv valves are located on this car.

Anyone have the same problem? Pictures would help lots! Thanks

Hey guys,

I did my own searching around, seems like the 2.4L in that year did not come with an EGR or PCV valve. Makes sense why I couldnt find it. That leaves me to believe the only way to lower the NOx is to either replace the Catalytic Converter and or replace the Oxygen sensors.

Some did, some didn't.


It controls oil fumes not NOX emissions. Look on the side of the block, under the intake manifold.


Only if it restricts exhaust flow. A new converter can mask the "problem", but the "problem" will kill the converter.


Not likely. A dead sensor will cause it to go into "open loop" (rich mixture) and make less NOX.

Under hood ducts intact and in place?

Engine overheating? Knock sensor causing excessive ignition advance?

Check engine light? Codes? History?

Post the test results.

Norm