Loss of Power getting on highway

[PPerson]

2002 Astro AWD with 159,000 miles.
A few weeks back the van just up and quit on the way home. Fuel pump was dead. $700 for a new fuel pump and the van is running again though the mechanic told me there was a whole list of codes. He cleared the codes and asked me to give it a few weeks and come back in, assuming that some of the codes would come back and any associated with the fuel pump would not.
With the original plugs, wires, distributor, rotor, & PCV, it was time to bite the bullet and jack up the front, pull the wheels off, inner fender skirts, dog house, etc. Overall the parts were not as bad as I thought they were going to be. Drivers side plugs took about 2 hours, passenger side about 45 min. Fixed the vacuum line for the fan control again so now we have airflow from wherever we want it and the rear heat works again.
Prior to the fuel pump dying we started to notice a howling noise on acceleration getting on the highway between 40-60mph and also a lack of power. Thought the fuel pump may have been the culprit but apparently not. The howl is very pronounced. I don't hear any knocking/pinging. Going up a long hill I have been putting it in 3rd to keep the RPM's up to maintain speed.
Idles very smooth.
Transmission was rebuilt at 100k.
Any ideas?
Thanks,
Peter

[chevymaher]

You did not fill in your van year etc.in your profile.That helps members know what you got,when brainstorming hopeful answers.If it has one and most do,check the egr valve see if it stuck open.That is a power killer.The howl sound could be just deep pedal driving because of the lack of power.

[Phantom]

You have some wolves or coyotes under the hood..err doghouse ....

Loss of power could be a clogged fuel filter , dirty air filter , vacuum leak , weak coil , various possibilities , have you checked for codes yet?

seems a good tech would have written down the codes before he cleared them

[PPerson]

I'm pretty sure the codes are written on the receipt for the fuel pump work, unfortunately my wife is out with the van right now.
Air filter is brand new.
Fuel filter was replaced within the last two years but could be bad.

Keep the ideas coming. Hoping to avoid another trip to the repair shop. Already spent alot of money on the van this year.
Thanks,
Peter

[Jasen]

If the codes are on the receipt you should be able to find them on one of these stires.

http://www.edgeproducts.com/product_images/customer_support_article-pdf-40.pdf

http://service.gm.com/gmspo/mode6/index.html

http://codes.rennacs.com/

Hey Burt, you should sticky these links, Yea?

[PPerson]

Here is a list of codes that showed up;
P0101 MAF PERF
P0135 O2 HEATER
P0137 02 CIRCUT
P0300 MISFIRE
P0442 SMALL EVAP LEAK
P0452 FUEL TANK PRESS SENSOR

Peter

[Phantom]

If you take van for about a 40 minute drive on freeway codes may come back on , some codes only set after van driven at about 65 mph for aprox 15 minutes , do you have a way to record the howling sound ? what may sound as howling to one person may sound like something else to another , howling would seem to indicate air passing through something , perhaps the doghouse is not tightened completely and allows air to come in around the seal ?

[PPerson]

Forgot how long ago I last posted.
Turns out the Catalytic Converters were toast. Had a garage replace the 'Y' pipe/converters assembly - $800.

Peter

[norohs]

Thank you for the update. I'm late with this I know, but it sure has helped.