New Kon owner. Lots of codes | problems...

[nimrod.sixty9]

Just bought a 1999 Yukon 5.7 with with a few issues. Runs fairly well, when cruising on the highway it runs great. At idle cold or hot, I can feel a bit of a miss.

Before getting the truck home I stopped at Advance to check the codes:
B0225
B0227
B0235
B0226
All the B codes had to do with LF Speed Sensor and Rear Speed Sensor (did not specify pass or driver)

P0141 - HO2S Heater Performance Bank 1 Sensor 2
P0155 - HO2S Heater Performance Bank 2 Sensor 1
P0161 - HO2S Heater Performance Bank 2 Sensor 2
P0304 - Cyl #4 Missfire

Im thinking whats causing cyl 4 missfire is causing the O2 codes. Would I be right? Where would you start in all this mess?

 

[lesterl]

O2 codes could be a blown fuse to the O2 heater circuit, or bad O2's, or bad wiring to them.

Cyl #4 missfire could be ignition or fuel, these Vortecs use plastic poppet injectors and they can plug up and lean out that cylinder, or stick open and flood that cylinder.

 

[nimrod.sixty9]

Been reading up on this Spider Injection; strangest crap Ive ever seen in a vehicle. Why in the world would anyone want to put this thing on here under the plenum no less?

Going to try out this expensive cap and rotor and see what happens.

 

[lesterl]

It was cheap..... They make a MPFI upgrade to the CSFI to put "real" injectors at the ends of the runners...... no performance gains over a running stock system, but no clogging up......

Might try to seafoam the intake real good if you havent changed plugs yet....

 

[nimrod.sixty9]

Dont know where you shop, or where you work. But I think that $70 for $.10 worth of plastic.

Do you have a link explaining this MPFI?

I had already done a Seafoam. Didnt really do much as I found out what was wrong. Inspected the plug in cyl #4 and noticed a very small crack on what I believe to be called the electrode (had another laying around). Also decided to check the gap and sure enough, no more than .035. Checked the rest of the plugs and low and behold all were incorrectly gapped. Regapped and no more rough idle or missing!

ABS light is also now off. Replaced the left front speed sensor with one I pulled from a JYard today. Never messed with anything on the rear.

Just drove the hell out of it; NO CODES AT ALL!

Still have an issue with the peddle pressure though. Goes to the floor but still seems to stop fairly well. Have to let into it fairly slow otherwise harder to push and less effective. Im thinking brake booster. Not really sure where to start troubleshooting. Thoughts, input, advice?

 

[lesterl]

Dont know where you shop, or where you work. But I think that $70 for $.10 worth of plastic.

WTH?

Do you have a link explaining this MPFI?

Nope, but basically you have 8 injectors in a fuel pod in the center of the upper intake, from the bottom of the injector runs a tube to a small poppet at the end of the stalk, this poppet has a clip that holds it in place in the intake tract. MPFI is where you still have the body, it is empty, the tubes feed down to (where the poppets used to be) the actual injector assembly and has 2 wires feeding each injector also (direct swap essentially). The injectors themselves dont plug up like the plastic poppets used to.....

I had already done a Seafoam. Didnt really do much as I found out what was wrong. Inspected the plug in cyl #4 and noticed a very small crack on what I believe to be called the electrode (had another laying around). Also decided to check the gap and sure enough, no more than .035. Checked the rest of the plugs and low and behold all were incorrectly gapped. Regapped and no more rough idle or missing!

How Did you seafoam? Pull the brake booster and pour it down/stall the engine when hot?

ABS light is also now off. Replaced the left front speed sensor with one I pulled from a JYard today. Never messed with anything on the rear.

Yea!

Just drove the hell out of it; NO CODES AT ALL!

Yea!

Still have an issue with the peddle pressure though. Goes to the floor but still seems to stop fairly well. Have to let into it fairly slow otherwise harder to push and less effective. Im thinking brake booster. Not really sure where to start troubleshooting. Thoughts, input, advice?

Bleed the hell out of the brakes. If that dont do it, maybe you have a bad Master cylinder? (when I say bleed the hell out of the brakes I mean alot of fluid too.....)

My .02.....