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last week i removed the cats on my truck put a single 2 1/2 back to a flow master and out 2 1/4 seems like my milage is falling bad my buddy said its cuz it needs that cat so the o2 can read rite truck is a 93 150 w302 and another question there is a sensor located on the back of the block behind the intake and under the fuel rail inlet is that a knock sensor
Did you retain the O2 sensors? or did you chop them off? I'm also thinking you might be suffocating the truck. Disconnect the exhaust system and see if it regains some mileage. As long as you keep the sensors and they are working correctly missing or hollowed cats shouldn't pose a problem. Check your connections...also check the airbox sensor, they easily fall out all the time and cause problems like reduced fuel mileage.
i kept the o2 sensor where it is dont think its suffocated it flows pretty good but did pull the codes out of the ecm p0334 egr closed voltage to high not sure if that means replace the sensor on top of it or replace the egr valve its self
That code comes up as # P0334 Knock Sensor 2 Circuit Intermittent (Bank 2). The EGR is easy to test, take it off the engine. Manually push the rod up...or is it down...whatever way it is seated make it do the opposite; and then put your finger on the vac hole and let go of the rod, if it closes shut its bad. if it holds its still good; if it slowly slides down...its going bad. They're cheap enough now I think only 50 dollars or so. I would go through and check your connections (electrical for emissions, and all your vac tubing). Also throw a bottle of seafoam in the tank, and replace the fuel filter; it can't hurt either way.
i just done the sea foam thing ill perform the valve check today so i wonder if that sensor missig on the back of the block 2 pin connection missing a sensor somebody told me that the knock sensor on a ford was in the distributor but im fairly new to the blue oval so im not sure thanks for the info
last week i removed the cats on my truck put a single 2 1/2 back to a flow master and out 2 1/4 seems like my milage is falling bad
How are you calculating milage and how much has it changed? FWIW the exhaust changes you made should help milage a little so if the milage is actually down that's not the problem.
Originally Posted by moostadon
Another question there is a sensor located on the back of the block behind the intake and under the fuel rail inlet is that a knock sensor
i check my milage by how much i put in the tank and what is on the gauge i put in 20 bucks and get bout 7 gallons run to work bout 60 miles round trip the fuel gauge is back where it was when i put gas in it i figure some where round 9-11 mpg
and since this motor has no provision for that knock sensor should i pull the upper plentium and drill the block and put one in or ust pull it all off and go to a carb and intake
Quick question, when you removed the cat, what do you do with the two lines attached to it? I'm debating removing my cat, but not sure what to do with these two 1" metal tubes?
I, personally, had my mileage plummet when I put a racy exhaust on my MG Midget. It should have reduced back pressure and increased efficiency. So, why did my economy go down? I loved revving it to hear the new exhaust, and burned more gas as a result. It sounded great. I bet your exhaust sounds great too, and if you are flooring the gas to listen to the sound, well, that may be your explanation right there....
and since this motor has no provision for that knock sensor should i pull the upper plentium and drill the block and put one in or ust pull it all off and go to a carb and intake
If the block doesn't have a spot for the knock sensor simply forget it and leave the wire hanging... it won't hurt anything.
You can't use the fuel gauge to calculate milage they're notoriously innaccurate. The right way is to reset the trip meter and then drive until you need gas again. Top up the tank like you normally do and then record the fuel required and distance traveled, that's your fuel milage. This depends upon the odometer being accurate though, if the truck has something other than stock sized tires on it the speedo(psom) has to be recalibrated first.
Quick question, when you removed the cat, what do you do with the two lines attached to it? I'm debating removing my cat, but not sure what to do with these two 1" metal tubes?
Remove them and the whole air injection system, it serves no purpose without cats.