Rich Codes

I Have A 1998 Chevy With A 5.7 Vortec V8 (ses Light All The Time)4 Months....rich Codes Po172 And Po175. Rough Idle, And Hard Starting When Hot(have To Put Gas Pedal Down).and A Very Bad Exhaust Smell Otherwise Runs Good.things I Have Done....checked For Vaccum Leak,new Spark Plugs Wires Cap And Rotor,checked Plugs (1 Dark Black On Even Side And Two Dark Black On Odd Side)cleaned And Put Back. New Coolant Sensor,cleaned Maf Sensor. Now Ses Light On And Off. Could It Be The O2 Sensors( 2 On This Truck)?or Could It Be The Fuel Pressure Regulator Or Leaking Fuel Injectors????is There Any Way I Can Test The Fuel Componets With Out Taking Off The Upper Intake Manifold?? Thank You For Your Help.

I Found The Problem On My Own.....the Fuel Pressure Regulator. Under The Upper Platnium, Leaking Gas Within The Motor...replaced,truck Is Like New!!!!!!

Newbe here!! I did all that too. A friend got me the whole "spider" freebie!! woo hoo! NOT! I installed it now it's running worse than ever, I guess I'll get a new fpr and put my old "spider" back in.

if you go with an adtermarket FPR. you may get undiserable results. That is what happen to me. I found one for $60 and the local parts store, put it in and got the worse gas millage ever. I was lucky to drive 150 hwy miles on a tank of gas. I ended up buying the one from the dealer for $100 and now my millage is back to normal.

Bit the bullet...orederd the updated mfi "spider" and delco fpr, installing today! Thanks for all the advice here, very helpful. I'll be posting some pics soon.

dumb question whats "spider" ?

Not dumb, Because I was going to ask the same question

I'm referring to the unit with the 8 injectors on it......looks like a spider to me..........

Help!! I had a shop install the new delco mfi "spider" fpr and o ring set, now I have a dead miss on 4 and 8??? Anyone had this happen? Could a piece of carbon or dirt got in the injector hole?Going broke fast, please help

Bad O2 sensor on right bank, $750.00 later it was a $30.00 part.......

Sorry to hear that; but thanks for posting the real problem part for others to refer to in the future!

Yea...Some scanners..."snap on" and mechanics for that matter can be misleading, O2 sensors are a good investment even on a perfect running engine.