Trying to get my Bonneville in good shape!

[T_Whittaker87]

Hello everyone, I do not post much but I come here for all questions I have about my Bonneville. I am away a lot for the Military and am currently deployed and now have the money to give my Bonneville the new life it deserves. I have read many posts on what I need to do for my Bonneville to keep it in good shape but I just wanted to get some more direct guidance on where I am at and what I should do next, any help would be greatly appreciated.

I am not home to over see the repairs and preventative maintenance which drives me crazy but my wife does drive my car so I want it safe and performing as well as it can.

03 SLE currently 128,976 miles

I recently have gotten the following done to my Bonneville.

-Upper and lower manifold gaskets replaced
-Upper intake manifold replaced
-Front wheel hub bearings replaced
-Steering shaft greased
-Front stabilizer bar links replaced
-Outer tie rod ends replaced
-Right front axle assembly replaced
-Coolant flush and fill
-Trans flush, fill, gasket and filter
-Oil change and filter
-Fuel filter replaced
-Front end alignment

Before I left, less than 6,000 miles ago

-Spark plugs and plug wires replaced
-Front brake rotors and pads replaced
-Thermostat replaced
-Valve cover gaskets replaced
-Battery replaced
-Front motor mount replaced

I am planning to have the rear brakes done shortly and have the tires rotated and balanced as well as the serpentine belt replaced.

The car currently has the check engine light on and the oil pressure gauge pegged (oil pressure sending unit?). I believe the check engine light has something to do with exhaust pressure, not sure exactly.

Any Ideas and knowledge you would like to share are welcome! thank you in advance.

[T_Whittaker87]

Also I got the steel coolant elbows put on when the gasket work was done.

[T_Whittaker87]

and an MAF sensor around 2 years ago. lol

[justin85]

can you post the codes for the check engine light? that would help narrow it down.

[T_Whittaker87]

I'll get in touch with the mechanic that did the repair and get back with that.

[T_Whittaker87]

He said he thinks it was p0420, the car runs well as of the last time I drove it and the light was on then and I didn't know any loss of power then unless it was very gradual.

[justin85]

will be gradual if the catylic convertor is going on it, you will know when the exhaust starts to stink like rotten eggs and hard shifting in transmission and rattling in center of car, would sound like a loose heat shield. but if its P0420 thats an O2 sensor bank 1 (O2 before the catylic convertor).
if nothing wrong with convertor, replace the O2 sensor before the catylic convertor, or both.

Hope this helps

[PilotScott]

Just wanted to say: Thank you for your service Whit and STAY SAFE!!

[T_Whittaker87]

Thank you for your help, any other maintenance issues I may have overlook that I could get knocked out.

Thank you PilotScott, it is my honor to do so.

[1tinindian]

will be gradual if the catalytic converter is going on it, you will know when the exhaust starts to stink like rotten eggs and hard shifting in transmission and rattling in center of car, would sound like a loose heat shield. but if its P0420 that's an O2 sensor bank 1 (O2 before the catalytic converter).
if nothing wrong with converter, replace the O2 sensor before the catalytic converter, or both.

Hope this helps

Just to clarify, on a "V" engine, there is a Bank 1 and a Bank 2, (The number of cylinder heads).
The before cat, HO2 will be "Sensor" 1, and the after cat O2 will be Sensor 2.

Leon