Mechanics

WHY AM I GETTING SEVERE HESITATION AND VERY POOR GAS MILEAGE?

2006 Honda Accord • 80,400 miles

I am experiencing a number of performance issues with my Accord. I had noticed these happening off and on about 8 weeks ago, but now they are constant from the time I first start my car and drive it to work in the morning, and then start it up and drive it back home everyday! It's very frustrating because I had experienced these issues with a 2005 Nissan Frontier pickup late last year and I ended up trading it in for a 2006 Honda Accord. Here is what I am experiencing.

When I'm driving in general, the car seems to hesitate a lot upon acceleration. I have to really press on the gas pedal to get the car to speed up. When it does, I notice that the RPM is at 2000 and it doesn't gain torque. I also notice the speed increasing at a slow rate, but it does speed up. The best way I can describe what I am feeling is the car is trying to struggle through a pool of thick molases. Very restricting.

As I accelerate for a couple minutes to gain speed and then let go of the gas pedal, I notice the RPM drop rapidly to about 1000RPM and then slowly raise up to 1500-1600 RPM. I really feel a hesitation when trying to accelerate any higher than 2000RPM. I can feel the speed increasing very slowly, but I don't feel the downshifting kick that you would usually feel when trying to go faster.

Also when the car coasts, it feels like it starts to slow down very rapidly on its own. You can feel the car slow down without even stepping on the break pedal.I can feel myself kinda lean forward as if I am stepping on the break. The break pedal feels kinda heavier than usual too.

At the same time all this is happening, I notice the steering wheel becoming harder to stear, the gas pedal suddenly needs more force to press down, and the suspension ride feels as if I have a cow or something on top my car and is putting a bunch of weight on the vehicle.

Here's the tricky part of all this.I have no CEL whatsoever and the car never feels like it’s going to stall at all! When I’m at a dead stop, the car idles smoothly. I don't know if this means that I don't have any error codes though. Would the CEL come on 100% of the time if there is an issue? Transmission fluid is new and there are no leaks or burning from the transmission. Spark plugs are new, air filter is new, but I don’t know about the fuel filter. The car has 80,400 miles on it, so I doubt it ever got changed before….

My gas mileage has gone to crap too! I filled up my tank with 91 octane gas. I’ve driven two 60-mile round trips to work, and I’ve already blown half a tank of gas! This is getting ridiculous and no Honda-specialized mechanic can figure the problem! What the hell!
I have experienced this with a Nissan Frontier as well and couldn't get it looked at before I traded it in for this Honda, so I never knew what caused all this. I am hoping that someone can help me with this. The Honda dealership techs continue to tell me that there is nothing wrong with the feel, and I know there is. Please help!
Avatar
Mlampa
September 23, 2011.




There are a few possiblities; With the bad gas mileage, the O2 sensors could be failing.
The problems with steering and scessories affecting engine would be related to the Idle Air Control valve, which changes parameters dependent on engine load. However, this is at low speed or idle.

Getting a trouble code scan can still bring back codes despite that the CEL is not on. Sensors can be within range as not to trip the CEL but the scanner might catch a code such as fuel pressure, that will shed some light on the problem.

You can check the fuel pressure manually by getting a test gauge. Most Advance autos or large auto parts store chains often have a loaner program for these. There is a test port on the fuel rail.

I think checking the fuel pressure and running a code check, as running a check should be cheap. Scanners can be had for under $100 now, would be the first step.
If the fuel filter has never been changed, that is a suspect.

I will keep an eye on this post for your reply.

OK, let's talk about the O2 sensors. If they are going bad or have failed, tell me in detail how this affects the engine performance. I know about the gas mileage, but how would the car feel like when I'm driving it?

Tiny
Mlampa
Sep 23, 2011.
The O2 sensors constantly check the air/fuel ratio. This ratio changes as RPM, engine load and other factors change and it follows a mapped curve to optimize the amount of fuel in relation to the timing curve.
This is all done at a stoichenetric value which is where the best fuel economy and best performane values meet.
This keeps things like throttle response, acceleration, engine power when accesories are on, etc. At an optimum level.
This is checked by making sure the aforementioned specifications are met and that as much gas as possible is burnt up in the engine and not wasted coming out through the ezhaust. When this happens, the air/fuel ratio is rich and too much gas is being used. When the O2 senor is hit with the O2 coming out of the exhaust, which should be a minimal value meaning air/fuel ratio is optimal becasue most of the oxygen was used in the compustion chamber. This in turn means the amount of fuel is optimal and the O2 sensor sends a voltage signal to the computer which constantly changes the amount of fuel to keep the air/fuel ratio at the stoichemetric value.
For example, your exhaust has a leak near the O2 sensor, it sees a lot of oxygen so it thinks that the engine needs more gas to use the oxygen up and have the optimal air/fuel ratio. Since the air is, "fooling" the O2 sensor into thinking the engine is running lean, it wastes gas and fuel economy will suffer as well as performance. Other things will happen like backfires out the exhaust.
When the oxygen level is too high, the O2 sensor thinks the engine is running lean as not enough oxygen is being burnt and the lack of fuel can damge valves, etc. So, the O2 sensor sends a voltage signal to the computer to put more gas in the engine by changing fuel injector pulse length, time injector is spraying fuel, or by changing the fuel curve by making it deliver less fuel in relation the the andgle of the throttle poistion sensor. This makes the air/fuel ratio richer in fuel and keeps it at stoichmetric when there is too much air in the ratio.
Perfomance will suffer in the same manner, but the chance for tope end damage is greater. Valves need fuel to stay cool and lubricated or they will, "burn up" and lose their seal to the head and leak.
I the lean situation backfires occur through the intake manifold.
If I put in redundant or you have any questions as I am too tired to read the message, please let me know and I will get back to you ASAP. The O2 sensors constantly check the air/fuel ratio. This ratio changes as RPM, engine load and other factors change and it follows a mapped curve to optimize the amount of fuel in relation to the timing curve.
This is all done at a stoichiometric value which is where the best fuel economy and best performance values meet.
This keeps things like throttle response, acceleration, engine power when accessories are on, etc. At an optimum level.
This is checked by making sure the aforementioned specifications are met and that as much gas as possible is burnt up in the engine and not wasted coming out through the exhaust. When this happens, the air/fuel ratio is rich and too much gas is being used. When the O2 senor is hit with the O2 coming out of the exhaust, which should be a minimal value meaning air/fuel ratio is optimal because most of the oxygen was used in the combustion chamber. This in turn means the amount of fuel is optimal and the O2 sensor sends a voltage signal to the computer which constantly changes the amount of fuel to keep the air/fuel ratio at the stoichiometric value.
For example, your exhaust has a leak near the O2 sensor, it sees a lot of oxygen so it thinks that the engine needs more gas to use the oxygen up and have the optimal air/fuel ratio. Since the air is, "fooling" the O2 sensor into thinking the engine is running lean, it wastes gas and fuel economy will suffer as well as performance. Other things will happen like backfires out the exhaust.
When the oxygen level is too high, the O2 sensor thinks the engine is running lean as not enough oxygen is being burnt and the lack of fuel can damage valves, etc. So, the O2 sensor sends a voltage signal to the computer to put more gas in the engine by changing fuel injector pulse length, time injector is spraying fuel, or by changing the fuel curve by making it deliver less fuel in relation the the angle of the throttle position sensor. This makes the air/fuel ratio richer in fuel and keeps it at stoichiometric when there is too much air in the ratio.
Performance will suffer in the same manner, but the chance for tope end damage is greater. Valves need fuel to stay cool and lubricated or they will, "burn up" and lose their seal to the head and leak.
I the lean situation backfires occur through the intake manifold.
If I put in redundant or you have any questions as I am too tired to read the message, please let me know and I will get back to you ASAP.

Question to the original poster. Did you ever get this resolved? I am having the exact same issue with my 2006 Accord LX with 136K miles. I have already dropped so much money in having repair shops look at this car. Thanks for any input.

David
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Tiny
Dave5008
Mar 12, 2014.

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