Newto4x4

hey everyone i have a 99 tahoe 5.7 engine so i have replaced alot of parts and have done alot of work, im looking to change out the sensor or plug and i cant seem to figure this one out ... okay on the right side of the engine, drivers side from looking or standing at the truck, right above the spark plugs there is what looks to be 02 sensor or plug i cant seem to find anything online about wat piece it may be, mine looks old rusted and in bad shape, it has 1 wire to a blue/black connecter... if anyone ever changed or knows what this is i appreciate a responce ahead of time

in2pro

I THINK that is a temp sensor... I don't have my manuals available at the moment but I can check later this evening....take it out and if starts weeping anti-freeze you'll know real quick...

in2pro

Attached , hope it helps

Newto4x4

hey in2pro, thanks for the reply, great engine diagrams you have right there, i think im gonna have to change both for the engine coolant switch/sensor theyre so old and the last of things i have not changed, but seriously that was handy, would u happen to have the oil pressure switch diagram as that needs to be changed also? appreciate the help bro

in2pro

I'll try and take a look this evening and post back

Newto4x4

thanks in2pro all that info above was accurate i changed them, engine coolant temp sensor/switch and now im gonna do the TPS, IAC, EGR, and the oil sending unit as the gauge since i bought the car has always been haywire...

Cliffjrs

Best to start with the grounds making sure they are clean and rust free. You'll save some money and headaches later. Start with the one on the frame under the drivers door.