Just purchased a 03 Blazer 4x4 4dr and I've been experiencing some issues.

1) Seems like my fuel gauge isn't working properly , I've attempted to track it down but it seems as if while driving any short distance (maybe 20-50) miles even just highway, it moves down to about 3 quarters of a tank . The fuel pump was replaced just a few months ago also, so I'm really not sure what more it could be .

2) Now for the codes that I have , since I know it's a generic code reader I have P0155 (Sensor heater core circuit malfunction) bank 2. Then the second one is P0459 (Emission Evap system ) . Not really sure about the evap one as I've never honestly seen the code and from what I've read online , it's the canister in the rear of the vehicle ?

As for the first code, I was trying to figure out , if I should just go ahead and replace both 02's rather than just one ?

3) I'm going to be doing a tuneup on the blazer I would hope in the next few weeks, what are the best plugs & wires to go with , I've been considering just going the AcDelco route but I'm looking for other alternatives from users on the site that have had great experiences with other brands .

4) I was looking on the cheap/free mods list, and I would really like to hear of someone on here who has actually successfully pulled that weird piece off the tb butterfly . My reasoning behind this is because I'm just under the influence that it will just throw codes by pulling it apart .

5) I was looking for some type of write up to improve my mpg, and I seen that some people actually seen results by lowering the vehicles , nothing major maybe a +1 . Others I've seen that people have done some other maintenance like cleaning up the egr valve ( is there a write up ).

Chi_Town

 

1) Fluctuations in the fuel gauge are almost always caused by a problem with the buffer, (electronic "shock absorber") in the fuel level sender. Aftermarket fuel pump modules use a cheap quality buffer. Installing an AC Delco or Delphi fuel level sender usually fixes the problem. It can be replaced without replacing the entire fuel pump module.

2) P0155 is indicating problem with the heater circuit in the passenger side upstream oxygen sensor. Following this flow chart will pinpoint the problem: https://blazerforum.com/forum/diagno...plained-35155/

P0459 is indicating a problem in the purge canister vent solenoid circuit. This is an electrical problem, not a mechanical issue, and not the canister. This will help you find it:
3) "I'm looking for other alternatives from users on the site that have had great experiences with other brands." You won't find any You're already having a problem with your fuel gauge, stay away from aftermarket stuff. Use AC Delco 41-993 plugs with a gap of .060", AC Delco cap & rotor, AC Delco or Autolite professional series wires. The Autolite wires have better specs and are cheaper than AC Delco.

4) There are no "cheap/free" mods that work. The throttle plate mod will cause the throttle to be very sensitive or "jumpy" on acelleration. It will not gain horsepower or improve performance. If the 8th character in your VIN is "W", the fuel injector upgrade will improve performance. If the 8th character is "X", the engine already has the upgraded injectors. Several other things will affect fuel mileage... brake drag, wheel alignment, tire pressure, vacuum leaks, clogged filters, low fuel pressure, excessive fuel pressure leakdown, low coolant temperature, etc.

5) The best way to improve fuel mileage is to keep the entire vehicle in good repair using quality parts. There are a few adjustments that can be done to "tweek" things, but require a high end scan tool to perform them.

Cleaning the EGR will help if it's not operating properly. Keep in mind that if the EGR valve is NOT operating properly, (opening, closing etc) a DTC will be set and the SES light will come on.... no light? No problem.

 

So if I were to bring it into a shop to have them try to figure out the emission situation they should be able to repair the issue , or issues ? Would that emission problem that corresponds with that code effect my gas mileage ?

And, I'm sorry that this took me so long to respond to, but I had the chance to check my vin and I do have the new injectors based on what you said about the vin code. I know on my normal weekly drive , I get roughly 200-250 miles to a tank, which is all county road driving at 55-65. Recently went to Appleton ,Wi with my gf and got 21mpg running premium, and the oil hadn't been changed and I still have yet to do the tune up . I just want the Blazer to be at 20mpg on avg that's all I really expect out of it for my daily commute of 50miles for 5days .

I did notice while changing the oil, that my front axles are leaking , Is that common to have both of them leaking at the same time ?

Tmugz

 

So as it seems, I can't find the ACdelco plugs in my area, I've called every parts store and they've told me that they are on back order... Is anyone else experiencing such a thing ?

 

Are there any other plugs members have used and received good results with ? I know in my 99 Tahoe with the 5.7 I used the Accel series plugs , I can't remember the part number but had great results, and I used the NGK's and had great results as well. I used to get 24mpg on the highway with that and 17 in town , really wish I could get similar results with the blazer for sure .

 

Try ordering the plugs from Rock Auto...same with the wires...usually the best price, although Amazon has good prices too.

As far as mpg....20 is the best you will get unless always going downhill. The S10 Blazer is and never will be a high mpg vehicle....especially the 4wd models......alot of weight being hauled around.

If either of the O2 sensors is not working....this will affect mpg. I would replace both of them. They can be a PITA to replace due to lack of space to turn a 7/8" wrench...and getting the electrical connectors unmated without breaking off the locking tabs!

Let us know what you find.

Good luck.

 

Wouldn't I need to rent a 02 removal tool to remove either of the 02's? And, I just want at least 20mpg to and from work that's about all I care about because my drive is around 50miles and constantly going 55 with 3 stops it should be reachable .

 

What o2 sensor would I need ?

Chi_Town

 

Diagnose and repair all DTC's. Tune the engine using AC Delco parts, have the front end aligned by a competent shop, make sure the brakes are not dragging, and no vacuum leaks. I have a 98 2 door, 220K miles, and an 04 4 door, 110K miles, both are 4WD, both are tuned using AC Delco parts, both have GU6 axles, (3.42:1 gears), both consistently get 23+mpg on the highway.

 

That at the very least gives me hope, I will get it into a shop asap, and have the front end looked at and have repaired what is needed, than just focus on a tune up . I know it needs a new rotor in the rear (D) side , but I was going to replace both , and see what the fronts are like . The front axles look like they are leaking, so im not sure if it's the differential or if it's the axles themselves .