P0171 & p0174

[doubleaction]

My SES light came on yesterday, so i decided to hit up the local Murrays and get a free diagnostic. After hooking up the diagnostic tool i received the following codes P0171 and P0174. A total of 4 codes, but each code came up twice. I checked with their Chevy service manual and the codes detail was that i most likely have a vacume leak somewhere. I found out that it could be from the MAF, or the intake manifold. I cleared the codes, and we'll see if it comes back on.

Anyone know exactly what could the problem?

Thanks, Josh

[1BADAIR]

maf, fuel pump, fuel filter

[ssgtgaines]

grab a can of brake clean and check for vacuum leaks first. I would pay attention to the bottom of the intake. if nothing present probably a maf. if there are no drivability issues the fuel system is probably good. good luck

[doubleaction]

grab a can of brake clean and check for vacuum leaks first. I would pay attention to the bottom of the intake. if nothing present probably a maf. if there are no drivability issues the fuel system is probably good. good luck

Yup the SES light is back on.....the car seems to drive the same, i havent noticed any changes. I will spray it down and try to find it.

[SSTODD]

Is the maf stock? aftermarket SLP or Granatelli mafs lean out our cars too much and can throw lean codes.
If you are stock, buy some maf cleaner (CRC) brand and clean the maf sensor wires but do not touch or rub on them, spray and let dry only.

[doubleaction]

ok so i found a hose...idk exactly what its called, but i know its part of the PCV system and its next to the firewall. Its all rotted our and its broken. I can hear and feel the vacume. Anyone know what this is called, and where i can get a new one?

[1BADAIR]

which side?
how big. there is a small vacuum line on the right that goes to the HVAC. big line on the lft goes to the brake booster
the pcv valve is in the front

[doubleaction]

which side?
how big. there is a small vacuum line on the right that goes to the HVAC. big line on the lft goes to the brake booster
the pcv valve is in the front

Its on next to the firewall on the passenger side. Its like a coupling or something and hose connects to it...there is deffinetly vacume in the hose.

[Schuby87]

If you follow the hose does it go to a valve cover or the throttle body?

[doubleaction]

If you follow the hose does it go to a valve cover or the throttle body?

i think it was the valve cover, but ill check tomorrow.

[doubleaction]

i took some pics today..

[doubleaction]

the first is just a pic of the engine, so that if someone sees somethin out of the ordinary to let me know..

the second one is on the drivers side, but i dont seem to feel any vacuum coming through.

[1BADAIR]

where is the pcv valve? its missin. it should be right at the intake in that bottom hose. it has a wire like bracket bolted on to hold it. if you had an ls6 valley cover it would loop around a hook to the cover right beside the intake port. if you have an ls2 then the PCv(restrictor) would be in the drivers valve cover
that bottom hose in the first pic should Y and goto both valve covers. there is a vacuum diagram on the left strut tower

[Schuby87]

where is the pcv valve? its missin. it should be right at the intake in that bottom hose. it has a wire like bracket bolted on to hold it.

On my car it was more towards the rear, around the second or third injector towards the back.

I replaced my PCV system with 3/8" emission hose, a "T", and PCV valve from the autoparts store for under $20. Not too bad considering a replacement from the dealer is about $100.