1995 Sunfire GT 2.3 DOHC QUAD 4

My Sunfire is having a problem with accelerating. Started yesterday with no power climbing a hill. More I would push down on the gas, the slower I would go. As I left off the gas it would smooth out, then
when I would push down it would die down. after making it to the top of the hill, it would smoth out. Made it home with no issues. But did notice if i would push down on the gas, it was dieing out. As long as I pushed down slow on the gas it was ok. When I got home, I put it in park. Next I stomped on the gas, and it would pop and miss. Today I changed the inline gas filter and the plugs. Also changed the Oxygen sensor. This car has 136,000 miles on it. I have been reading my service manual for this car. Could it be the EGR valve or the Throttle position Sensor.I'm guessing! Could someone help?
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So - what happened after you changed the plugs?
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This engine does not use an EGR valve.
Sounds like a coil pack to me.

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After changing the plugs, their was no change. I even layed the coil pack to the side and ran plug wires to the plugs, and checked each plug with a test light as I gave it gas. The spark was strong on each plug. I even took out the Injector regulator and checked the screen. That was clean. It seems that the fuel pump is fine. I had a lot of pressure. Also started right up after checking it. Bob
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Having no codes, & attempting a guess, I'd have cat. convertor checked. A stopped up exhaust can cause those exact symptoms. When it is a stopped exhaust, you would hear a swooshing sound(as it exits tailpipe) while accelerating & not gaining speed s
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There is no check engine light on. If it's the Cat converter. How do you check it? Could I take out the o2 sensor out before the Cat and see if it runs better?
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My Sunfire

Don't think that would tell you anything. Muffler shops test the convertors, sometimes by hand: bump on the COOL cat and if it rattles inside, they know the insides are all to pieces and bad. Also, they check difference in pressure going in relative to that going out, which can determine whether it's good or bad. We generally out here in the field don't have the tools to do this pressure-checking: we pretty much know from 'feel', and from the 'whooshing' sound under acceleration, and from experience when one is bad. So we let the muff. shops verify and replace if needed. s
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My Sunfire

Throttle
from
if
Usually if the converter is plugged the engine will run hot and smell hot. And it gets worse quickly. Exhaust shops check the converter with an infrared thermometer.
Al
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Al and All I think we"re getting somewhere. I did notice it smells hot after running awhile. So I took out the O2 sensor and started it up, Ran a little better. So could I drop down the exhaust after the manifold, and start it up. I have my ear protection ready! Will it breath better to tell me that's the problem? Bob
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If the converter is plugged and you drop the pipe the engine will wake up instantly. If you find it is the converter, don't forget the muffler will sometimes get plugged with media from the converter. If you're doing it yourself, disconnect the converter where the hot exhaust won't burn something nearby. It gets very hot very quick.
When you had the O2 sensor out, was the exhaust coming out of the hole with a lot of force or pressure? If the converter is plugged it will.
Al
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wrote in message

normally an exhaust shop will drill a small hole in front of conv., put a pres. guage against it, and have someone gun the engine while checking for back pres.......,then he will (oops, or she) weld over small hole in about 20 seconds............free, everywhere ive ever been..........be careful running eng. with exh. unbolted at flange. as stated, gets real hot real quick!..............kjun
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THANK YOU EVERONE! The Cat was plugged! The front area was broke up, jammed against the back screen. Put a new cat on. "WOW" what power now! I hope other people reads this. I think this was plugged for a while. Cost $80 to replace! Thanks again Bob
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