99 Regal GS - O2 Sensor & Tune-up

[87gninpa]

My daily driver just hit 100k. I did a full tuneup last spring @ 75k; plugs, wires, pcv, fuel filter, etc.... I put regular copper plugs in, but now that I'm driving about 25k a year I want to put the factory spec iridium plugs in so I dont have to change them every year, whats the Delco part number for them?

Also, I want to change the O2 sensor, whats the best way to get to it? Go in from the top with a O2 sensor socket? I'm only planning on changing the upstream sensor, as the rear sensor usually doesnt have much to do with mileage or A/F ratio. Any help appreciated.

 

[flyboy367]

screw the factory spec plugs, use autolite 104. use a o2 socket from the top, just watch the wire on the new one.

 

[87gninpa]

I have the 104s in there, but i really dont feel like changing plugs every year on this car.

 

[flyboy367]

then you might as well not change them at all. stock is ok, but still should be changed each year. i change my plugs in the spring, summer and fall. im also running 14psi of boost and hi octane but still way better then stock. the 104 are a little cheaper then stock and take 15 min to change. how bad is that once a year. i also clean my air filter every 3 months. like my car running right.

 

[87gninpa]

The stock iridium plugs are good for 100k. Car is stock and staying that way, I dont see a need to change them every year.

 

[chuckross1957]

I would not be concerned about replacing the O2 sensor unless you have a code fail indicating a problem with it. Remember you have a back up sensor to make sure it is functioning properly. We have almost 130,000 miles on our 99 GS with the original sensor. I agree with using the iridium spark plugs. I always use high quality spark plug wires. If you have the original coils inspect the posts for corrosion. If you find corrosion you should consider replacing all 3 coil packs. I always use the economy coils with the aluminum posts as replacements.

 

[RegalT-type85]

250K on my old GS. the O2 was never a problem and i ran her hard. Sold her still running great. Did you do a U bend delete? as for the plugs, I understand about changing plugs, go with whatever you want.(lasts) I use to run NGKs always lasted me i was stock boost level. As for coils i used summits coils, not sure if they sell them still but should or might be under different make now.

The only reason i mest with the O2 at about 220k was to install the u bend delete pipe. Took it off put the same o2 on the U delete pipe.

 

[87gninpa]

I was only going to swap out the 02 as a maintenance item. I've hear they should be done @ 100k. If not, then great I'll just keep it in for now until it goes bad.

 

[RegalT-type85]

If you want to freshen up the a sensor or two, nothing wrong with that IMO. Do it, if it's what you thinks best. Again only reason why even mest with mine was to get the U bend delete pipe, which all SC3.8 should a must IMO.


I would change out the SC (nose) oil and bearings use new ones(green ones) at 120k.