my crossfire only runs good if u step on the gas but once you make a stop and try to gain speed it starts to bog down.. i get the code 44 lean exhaust.. could it be that my CAT is clogged? and i need to replace the O2 Sensor? .. car works fine wen its cold but wen it warms up then it starts with the problem
Help

 

Theres a good chance it may be your O2 sensor. Reason is the car runs good cold and full throttle. When the cars cold its operating in open loop mode which means the O2 sensor is ignored. At full throttle the car should run on the rich side however since narrow band O2 sensors cant read that A/F ratio the ECM knows to ignores the O2 sensor at WOT. If the O2 sensor were bad it would make scene that the symptoms would clear up under these circumstances.

 

Check for a major vacuum leak or exhaust leak before the O2 sensor first. If none are found, change the O2 sensor. That should help. It may be just old or contaminated. Does your engine burn any oil at all? Even just a little on cold start-up? After awhile, that can contaminate an O2 sensor and it won't read properly. If thats the case, it will just contaminate a new one after a period of time too.

 

Well the engine is new and the car sat like for around 9 years before i started restoring it. and yea no leaks everything is fine. new sensors and all just that lean exhaust and the bogin down wen warm.. the only thing that wast changed was thet O2 sensor and the Cat.
ima head out to napa and get me a new O2 sensor.. ill let you guys know how it goes
thanks for the advice

 

well i replaced my o2 Sensor and i still get the code 44? what else could it be?? the car bogs down but not as much what can it be?? help

 

A few things to check for:
-low fuel pressure-a common C/F problem,modifications
needed to check..
-wrong(305)injectors-350 should have#5233770 front
/5233775 rear-the #s are under the plug and may be
hard to read.
-wrong(305)chip-not sure how to I/D GM chips between
305 and 350(vette)chips..-when i did my 350 swap an
'82 vette chip was used(for '83 ECM an'84 vette chip
is needed)

 

hmmm never checked the fuel pressure. any ideas how many lbs should it be at?? and how should i check the pressure?? by the fuel filter?

 

The pressure should be taken at the pipe between the
two throttle bodies-there is no fitting to do this on the
factory pipe,one must be added.For mine i took a 1/8"
pipe fitting,brazed it onto the fuel pipe,drilled a tiny
hole into the pipe inside the fitting,added the gauge.
IIRC,the factory specs 9-13 psi as ok but many C/F
tuners have found they run better at around 14-15
psi...
often when the stock pump is found imcapable of
maintaining the set pressure,a TPI pump is used as
an upgrade.
To turn up the fuel pressure,the pressure regulator
on the rear throttle body needs to be taken partly
apart and modified to make it adjustable.

 

Would u pliz post some pics of how u did it?
it sounds kind of complicated and im not really good at this
im learning my way up haha
if u would post some pics i would apreciate it so much

 

couldn't find any good pics of the pressure gauge
(may take some fresh ones if i can round up my camera
)
meanwhile,a sure sign of low pressure is an off-idle
stumble(does your car do that?)

 

Oh oK
Actually Yeah It Does Stumble Some Wat But Sometimes Worse Than Others.
Also I Think That The ECM is not sending the O2 Sensor Voltage. Might My ECM Be Bad too?

 

Actually it's the o2 sensor that sends voltage to the
ECM..-it's a very low voltage signal of less than 1
volt.When i first swapped in my L83 CFI corvette
engine,i accidently left the o2 sensor disconnected
-still ran decent,though the CEL lit when the engine
got up to temp-o2 sensor can only adjust mixture
within a fairly narrow range.
ECM problems are possible but very rare
What do the plugs look like-do they indicate a lean
mixture too?
Also,does the fuel spray "cone"from the TBI nozzles
look nice and even between the two TBIs?

 

Yes The Cone Pattern Is Good The Injectors Are Fairly New.
uhm about the plugs i havnt checked them at all.. what should they be looking like? if ts lean should they be grayish?