Need help/assurance.

[Apollo5883]

Hello to all. And thankyou for reading my post. Here's the deal. I have a 97 Pathfinder with 167k miles on it. Just a week ago, my RPM gauge starting acting up. It dances around all over the place, literally. I called the local mechanic, and he said he thinks it's the sensor on the the transmission. Ok, I called the Nissan dealership down the street, and the guy there could not name the part/sensor i needed. But, he said he had something called a "Revolution" sensor that goes on the transmission. A lil research and I found that there's a "speed" and Revolution" sensor on there. Im almost positive that it's the Rev sensor I need. Could someone Please confirm this for me before I buy? Thanks.

[Towncivilian]

If the revolution sensor were failing, you would have a P0720 transmission code stored. Is either the "SERVICE ENGINE SOON" or "O/D OFF" light solid or blinking when you are driving? Follow the diagnostic procedure on page EL-90 of the factory service manual to determine whether the tachometer itself requires replacement.

Welcome to NICOclub.

[Pathfound49]

My experience with a speed sensor going bad is that the speedometer will read zero, but the tachometer still works fine.

[Apollo5883]

If the revolution sensor were failing, you would have a P0720 transmission code stored. Is either the "SERVICE ENGINE SOON" or "O/D OFF" light solid or blinking when you are driving? Follow the diagnostic procedure on page EL-90 of the factory service manual to determine whether the tachometer itself requires replacement.

Welcome to NICOclub.

The O/D Off light is not on but the check engine light is solid. But when I had it checked, the mechanic told me that this was for the Knock sensor. I have a new knock sensor to replace the faulty one soon. But thankyou for the link, I'm gonna check it right now.

[Towncivilian]

Have the engine codes pulled at an auto parts store such as AutoZone and post them here.

Do you run anything higher than 87 octane? If so, that may be causing your knock sensor code. Higher octane fuel is more difficult to ignite and the VG33E cannot advance timing far enough to take advantage of the higher octane; it was designed to run on 87 octane.

[Apollo5883]

Have the engine codes pulled at an auto parts store such as AutoZone and post them here.

Do you run anything higher than 87 octane? If so, that may be causing your knock sensor code. Higher octane fuel is more difficult to ignite and the VG33E cannot advance timing far enough to take advantage of the higher octane; it was designed to run on 87 octane.

I went to both Autozone and O'Reilly tuesday and both hooked the comp to my truck. Both stores showed the bad Knock Sensor, and as well as a bad Oxygen Sensor(bank One). But, they did not show me a code. Also, I checked the link provided to me by a fellow replier. In so, I checked the fuse, which is a 7.5 amp, it was fine. This is leading me to think that I will need to either run it to the Dealership and let them hook it up to a better machine. Or, Try and locate the sensor and go from there. Also, I only run 87 in my truck, never any of the higher grades.

[Towncivilian]

Strange, the AutoZone near me printed out a small receipt type thing with the code printed on it the couple of times I got codes pulled. Go back and request that they provide you with the specific engine codes. There's no need to waste $90 for a dealer diagnostic at this time. This will allow me to link to the correct oxygen sensor to replace. If it's an upstream sensor, the air/fuel mixture may be incorrect and that would cause poor vehicle performance, fuel mileage, and possibly the knock sensor code.