im new to blazer forum. i have a 2000 LS s-10 4x4blazer with 136,000 miles. just recently replaced fuel pump, fuel filter, spark plugs, wires, cap and rotor, and had a fuel injector service done. also replaced air filter with a drop in k&N and now for some reason it seems to run a bit smoother but still has a little noticeable hesitiation and worse gas mileage than before the tune up. tires say max psi is 50 so they are pumped up to 50 is that what your supposed to do is go to the max??? i dont know what else to do besides maybe the 3 oxygen sensors but i dont have a check engine light. can an o2 sensor go out and not throw the check engine light on. if anyone has some advice i would love to hear it and fix this problem. thanks

 

My truck almost had the same thing done to it and I noticed that too. I had the spyders updated though. I think in my case that the new updated spyders run richer than old outdated. It may be that the old one were clogged and ran lean. MY TWO CENTS.

 

you kind of lost me on spyders??? what are they??

 

the fuel spider is the black thing on top of your intake manifold that actually injects the fuel into the manifold

 

How comfortable are you at working on engines? I would think cleaning the EGR valve and mass airflow (MAF) sensor might help, and check the fuel pressure. BTW, do not run the tires at maximum pressure. That's just going to give you squirrelly handling and a rough ride. When they're cold, set the front pressure at ~34psi and the rear at ~32psi. Any more questions, feel free to ask.

 

ok i will give it a try. you would think after replacing all that you would see quite an increase in gas mileage...guess not. just got to find the posts saying how to go about cleaning those. thanks. any idea on the o2 sensors though???

 

Here's a thread for cleaning the EGR. The MAF is located just behind the air filter box in the air duct. Here's a thread on cleaning it.

 

thanks rriddle3i appreciate your help