check engine- cyl 4 misfire & knock sensor tripped

diamond · Oct 24th, 2002, 05:11 PM

Hello fellow enthusiasts!

on my 98 altima,

the check engine light came on and the ECM says it is a

Cylinder 4 misfire
&
Knock sensor was activated

I have already:

replaced spark plugs, wires, rotor & distributor cap

replaced fuel filter

changed oil

Any ideas whats wrong?

thanks in advance,

Diamond 242

2000SE · Oct 28th, 2002, 03:15 PM

Bad knock sensor.

Cheap gas.

Hows it running.

Overheating--replace thermostat and flush coolant.

Check timing.

Have fuelinjectors cleaned.

BORNGEARHEAD · Oct 28th, 2002, 07:30 PM

Check the resistance of the injector on that cylinder. I have seen a lot of knock sensor codes stored on the ecm's but they don't usually set a check engine light. I would just be concerned with the cylinder misfire. If you fix that and clear the code I think you will be fine.

diamond · Oct 29th, 2002, 11:05 PM

thanks for your suggestions...

my car was running fine- no performance/power loss.

when i reset the codes, the fuel economy crapped out.

other than that, right now it runs fine.

Diamond

diamond · Nov 25th, 2002, 05:23 PM

It turns out it was the intake manifold gasket...

good thing it was under warranty.

Diamond