2008 GMC 5.3, non FF, 1500 2WD Tune Up?

[08 GMC]

So  I’ve got about 95k mikes now and was wondering if I should change the plugs and wires? Runs fine, gas mileage is shit. I get 15 ish on the freeway, LA to SFO on I5, for example and every now and then at idle in a drive through I’ll feel a little roughness. Guess it could be the A/C compressor then then again the A/C isn’t on that much to account for it. 

 

So im thinking, over 90k it’s probably a good time to change the plugs and wires. Looks like th AC plugs are the best choice? Although I don’t know where to source them from. 

 

Any other tune tune up ideas? I’ve ran few tanks with the Lucas Oil fuel injector cleaner. Hasn’t made any difference. 

 

Brings another idea. Injectors. Are they a bitch to change? Necessary consideration?

 

Truck is a 2008 GMC 1500 5.3L non flex fuel 2WD. 

 

Thanks

[dsr611]

100000 mile maintenance schedule recommends replacing spark plugs and inspecting wires.  Go with OEM plugs/wires.  The plugs come pre-gapped and you can get them at any auto supply stores (when I changed them I got them at O'Rielly's) or order from any online retailer (RockAuto, Amazon, Ebay, etc).  Same thing with wires.

Fluid and filter changes

Inspect/replace drive belt

 

 

[swathdiver]

LY5 motor.  Change all your fluids and the plugs and wires and use GM OE or ACDelco Professional parts.  If mileage is still poor, it's probably your cats.  Get a good scan tool and check the condition of them and the O2 sensors by graphing their performance.  Also check for vacuum leaks visually and by watching the Long Term Fuel Trims and graphing the O2 sensors again.

[08 GMC]

3 minutes ago, swathdiver said:

LY5 motor.  Change all your fluids and the plugs and wires and use GM OE or ACDelco Professional parts.  If mileage is still poor, it's probably your cats.  Get a good scan tool and check the condition of them and the O2 sensors by graphing their performance.  Also check for vacuum leaks visually and by watching the Long Term Fuel Trims and graphing the O2 sensors again.

Never considered the cats. For a CA vehicle they are going to be expensive 

[swathdiver]

7 hours ago, 08 GMC said:

Never considered the cats. For a CA vehicle they are going to be expensive 

I have Cali emissions and the Magnaflow Y-pipe and cats are about $100 more than regular for the privilege of CARB numbers.  "Got Exhaust" will make you a great deal.  I picked up 5.5 horsepower at the rear wheels.   

[08 GMC]

2 hours ago, swathdiver said:

I have Cali emissions and the Magnaflow Y-pipe and cats are about $100 more than regular for the privilege of CARB numbers.  "Got Exhaust" will make you a great deal.  I picked up 5.5 horsepower at the rear wheels.   

Hmmmm.. Last year my nephew had a HHR and the cat went out.  Well like an idiot, he let the exhaust shop talk him into a new cat, mind you the car was 6 yrs old and 70k miles at the time fully under warranty, the shop put a non CA cat on and backwards at that. Couldn’t pass smog and I couldn’t find a place other than the dealer to buy another one that was legal..

 

I’ll look at the “got exhaust “

 

Thanks

 

[08 GMC]

I purchased as set of AC Delco 41-162 spark plugs and a set of AC Delco 9748RR Plug Wires and changed them.

 

The plugs that I removed were the AC Delco 41-985 plugs.

 

Are these roughly the same plug???

 

Thanks

[swathdiver]

20 hours ago, 08 GMC said:

I purchased as set of AC Delco 41-162 spark plugs and a set of AC Delco 9748RR Plug Wires and changed them.

 

The plugs that I removed were the AC Delco 41-985 plugs.

 

Are these roughly the same plug???

 

Thanks

Yes, the 162 is the current replacement for the 985. 

[08 GMC]

Thanks. Could not find any details on the plugs and therefore was clueless