20 Most Recent 2002 Nissan Xterra - Page 6 Questions & Answers

I had the same problem so I dismantled my engine and found out both my heads were cracked allowing fluid to enter the combustion chamber therefore foreign fluids were gumming up my pistons causing me to lose power up hills and so forth. If you are a good mechanic replace your heads and your problem will be solved.

Yes, a knock sensor can cause the check engine light to come on. I would change out the sensor and see if you come up with any other codes.

check brake switch at break pedal.

You need to bleed air out of cooling system

Have the ABS codes pulled, this will give you an idea of what is going on. It sounds like a faulty speed sensor, but check codes 1st.

Here's a link to your engine number.

Sounds like TPS sensor. If you replaced the TPS sensor you have to put a relearn program on it again to calibrate the sensor. If you don't have a programmer or know someone you have to take it to a shop and have it done takes literally 5 min

Most of the time the wire to the abs sensor on the wheel hub dry rotts or gets cut and can cause this. Does it give you a code number when you put an engine test device on it? This will help me out more

Describe the problem a little more. But there is a relay but lets try simple things first. Turn the key to on position and listen to see if you hear the fuel pump running... It should sound like a hummm lasts about 2-3 seconds. You can also disconnect the low pressure fuel line and turn key to on position to see it fuel pumps out. If it's working next bet would be to check your fuel filters and replace them they are cheap and you prolly have 2 or 3 different ones they usually run on the fuel lines underneath the vehicle 1 may be under the good and in or on the fuel tank. Could also be your mass airflow sensor or TPS sensor or maybe clogged injection. Again I need more info on what it's doing

sounds like a bad ground or a break in the wire harness