p0401 and p0442 code

[Timing]

Ok so first thing i was getting only the p0442 code when i got the car so my first thought was gas cap i replaced it and reset the light and it came back on. I read the codes again and i had that same code but then the p0171 code came up i cleaned my maf egr and pcv and reset the codes. Ive also replaced the spark plugs wires fuel filter changed oil tranny fluid filter oil pan thermistat coolant sc oil and made my own air intake with a larg spectre filter and pvc pipe and now my code came back up i had it read again after the p0171 code had gone away it came back up[ with the autozone scanner. so my initial thought was has to be maf. I ordered the maf and ill have it on monday but for **** and giggles i read the code tonight with my machine at work(much higher grade machine than autozone) and instead of the p0171 code i got p0401 and th p0442 code again and also some traction control code im really not worried about. Im stuck on this and need to get a sticker. Any help would be greatly appreciated.

2000 pontiac gtp

[dsmuts]

What car do you have? What do those codes mean? I'm to lazy to look it up for you.

[Timing]

Another thought my mpg is absolute crap. Im getting 16-17 according to the gauge. I know this can be a little off but shouldnt i be getting atleast 20-23 mpg?

[dsmuts]

depends on your driving style and where you drive. I get 24ish driving back and forth to work.

[Timing]

depends on your driving style and where you drive. I get 24ish driving back and forth to work.

the highest ive got was 18 when i was going 55-65 on highway coming from work basicly not pressing the throttle at all

[dsmuts]

isn't the 401 code for the egr or something?

[Timing]

isn't the 401 code for the egr or something?

yes and the 442 is typicly gas cap and 171 is bank 1 lean so could be vacuum leak maf o2 exaust leak or various other things

[dsmuts]

vacuum leak around the egr? That's where i would start. Check all your vacuum lines while your at it. If the egr is messed up and your running really lean it'll kill your gas mileage.

[dsmuts]

also your maf probably isn't bad.

[Timing]

ya im very confused on this ive replaced the egr gasket and cleaned it up and sprayed all over the vacuum lines with carb cleaner with no results, im thinking smoke test is my only option to narrow things down

[dsmuts]

When my maf went bad last week i got the 102 code. Your egr could just be bad and be stuck open and it'll cause you problems.

[Timing]

When my maf went bad last week i got the 102 code. Your egr could just be bad and be stuck open and it'll cause you problems.

is there a gaurenteed way to check this?

[dsmuts]

I'm pretty sure there is a way to check with an expensive scanner to make it open and close manually and look at it. I wouldn't go throwing parts at it and hoping you fix it.

[GTP in RTP]

Pull the egr hose that goes in the manifold. It will have a crack in it. This will throw the p0171

You have to remove it and look at the edge. Carb cleaner will not find this.

[Timing]

Pull the egr hose that goes in the manifold. It will have a crack in it. This will throw the p0171

You have to remove it and look at the edge. Carb cleaner will not find this.

This was my exact thought are there gaskets on that hose?

[GTP in RTP]

no, just flared ends that crack.

[GTP in RTP]

one other thing to check is the screen on the tb. Is it there or missing, sometimes if it is removed idle will be rough.

[Timing]

Idle isn't rough but that screen does have a few breaks and indents in it

[GTP in RTP]

The screen provides laminar ( smooth ) airflow across the MAF, helps the maf to be more accurate. Get one at the jy next trip.

[Timing]

The screen provides laminar ( smooth ) airflow across the MAF, helps the maf to be more accurate. Get one at the jy next trip.

To arrow morning ima check out that hose replace that screen and was thinking about ripping th egr off this gp with only 28k on it any idea what an egr usually goes for in th jy?