Hi Guys,

My gas milage went don the drain along with my acceleration..My 95 E420 does not respond fast to kickdowns and accelerates either sluggish or slow depending on how I step on the gas pedal, (hard and fast = slow start, slow and steady = even but slow acceleration, not terribly slow but not good either). One the car is rolling high speeds are not an issue, its just getting to them from a dead stop..However no matter how smooth I try to run it the car is swallowing the gas like nothing..about 12mpg..

I have new OEM caps/rotors, spark plugs and wires and no vacuum leaks..

I got a KS code a long time ago but has not returned since I cleared them 2 months ago..No CEL light on as well..Could this be the EGR, MAF, O2 sensor Throttle actuator or the KS that went kaput but still haven't turned the CEL light on..??

Any help appreciated..this LOW milage is not fun at all..

THxz,

DH

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"The bitterness of poor quality remains, long after the sweetness of low price is gone..http://www.peachparts.com/shopforum/...milies/eek.gif

My guess (1st) would be: Take a look at the fuel pressure. If the fuel pump is dogging out (pressure is down from normal), then you're not getting the right amount of fuel when you call for it...it could also be (2nd) a fuel-check-valve or (3rd) the fuel filter.

Those would be the first items I'd have checked out if you can't do them yourself...

Good luck!

__________________

M. G. Burg
'10 - Dakota SXT - Daily Ride / ≈ 172.5K
.'76 - 450SLC - 107.024.12 / < .89.20 K
..'77 - 280E - 123.033.12 / > 128.20 K
...'67 - El Camino - 283ci / > 207.00 K
....'75 - Yamaha - 650XS / < 21.00 K
.....'87 - G20 Sportvan / > 206.00 K
......'85 - 4WINNS 160 I.O. / 140hp
.......'74 - Honda CT70 / Real 125
.
“I didn’t really say everything I said.”
. . . . . . . . . . . . . . . . . . ~ Yogi Berra ~

cat could be clogged....

__________________
All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic

I will check to entire fuel system this week and see where that takes me..how can I check for a backed up cat if I am not getting any CEL light?

DH

__________________
"The bitterness of poor quality remains, long after the sweetness of low price is gone..http://www.peachparts.com/shopforum/...milies/eek.gif

Oh, forgot to mention the car has 131K miles..

__________________
"The bitterness of poor quality remains, long after the sweetness of low price is gone..http://www.peachparts.com/shopforum/...milies/eek.gif

With the decrease in fuel milage, are you getting a decrease in power?? Other than actually removing the pipe and driving it, I"m not sure how one would check that...

As I live in an area where the Gov doesn't care about cars that age, I'm just going to gut my cat and be done with it...

__________________
All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic

02 sensor failure is supposed to trip the light, but a faulty 02 reading causes mpg to drop.

__________________
- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600

Could it be cold weather.My S is burning fuel do too running rich(liked choked) because of cold temps.

__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran

How's your exhaust sound? Any louder?

An exhaust leak will also cause that doggish performance.

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2008 E350 4matic / Black/Anthracite

------------------------------------
Gone but not Forgotten:
2001 E430 4matic, 206,xxx miles, Black/Charcoal
1995 E320, 252,xxx miles, Black/Grey
1989 260E, 223,00 miles, Black/Black

That makes me suspect:

* A plugged catalytic converter.

* One of the two fuel pumps is failing or dead.



.

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

take out both front o2 sensors and drive it.if plugged cat that will relieve pressure.

__________________
David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
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