need some help diagnosing

K, ill try to make this short. 90 coupe 5.0, 73mm c&l with 19 pound tube and stock injectors. it does have a adj. fuel press. reg. 65mm bbk throttle body and spacer. prof products intake. ported gt40 head (cast) non p. steeda #19 cam. full length headers and full exhaust. pulleys and a conical air filter from autozone.

just got the car a few months ago. has had a whistle about 1/3 throttle since ive owned it. reading these forums has lead me to believe that it was the throttle body. now im getting codes 41 and 91. which is system lean or no o2 switching. i also have codes 33 koeo(egr) and a code 21 koer(ect). the car smells pretty rich. and it bucks quite a bit at cruising speeds. runs pretty good full throttle.

i did test the ect and the voltage at the sensor was 1.0v at around 160 degrees, which indicated a good reading. i have sprayed the entire engine down with carb cleaner at idle. no drops in rpm. (which im thinking its not going to since its not whistling til its under load).

not sure where to go from here. i dont have all the tesing equip. to test vac. and fuel press. just hoping someone has been through this same situation and can tell me their outcome.

thanks for reading all of this crap:damnit:

i actually called c&l about changing tubes when i put my 24 pound injectors in. they did say that a conical will cause a lean condition. but its the same with a stock mass air meter.

as far as the whistling sound. i personally think its a vacuum leak. but after reading numerous threads about whistling t/b's i wasnt sure. since it only whistles under load. how can i pinpoint where its coming from? any suggetions?

im headed over to a friends house tomorrow to set my fuel pressure. he thinks its causing alot of my problems. reason being he thinks the cars is running rich because it like alot of timing. i can set it a 20 degress initial with no problem and it runs better.

I dont know. i havent owned one in years and im just getting back into it.

k, update! fuel pressure was set at 55lbs i think to compensate for the 19lb injectors. whice it was loading up and bucking crusing around and fine when i hammered it. now its set to factory specs i think 42lb. and it drives better and doesnt stink. but i lost hella power and i think this is why the car like so much timing when i had the pressure turned up so far.

does this sound right?