Fuel economy has gotten worse.

K3Ntegra

Member
The low fuel warning light now comes on after 245 miles. Before it was typically around 275 miles. This means there are 3+ gallons of fuel left in the car. I know the instrument readings are working, because I end up having to add 10 gallons of fuel when the light first comes on. Fuel tank is 13.2 gallons in volume.

I noticed this after switching back to conventional oil.
After using synthetic for 15,000 miles (3 changes after 5,000 miles), I decided to switch back to conventional oil, which I had been using for 40,000 miles. I switched back to con/dynoil, because the car was leaking twice as much with synoil, and there were oil spots below the engine, on the tarmac. This is likely due to deteriorating seals, and therefore switching to synoil was a big mistake as well as a waste of money, since I couldn't go 10,000 miles without having to add 4 quarts between each refill.

A check engine light came while I was driving home from work. Shorty before that, the car vibrated 15 seconds while it was idling at a traffic light.

I took it to a mechanic who said it was a 1399 error code. He cleared the code and said if it comes back on after 50 miles, the EGR would have to be cleaned up and a tune up would be necessary. The catalytic converter may need to be replaced if the EGR cleaning didn't work. I passed emissions testing last September. I notice gas fumes in the cabin sometimes. It's been over 200 miles now and light didn't come back on.

The fuel filter was replaced last year.(changed 20,000 miles ago).

Distributor, iridium spark plugs and cable (both changed 5000 miles ago), mid pipe exhaust, one of the engine bay gaskets (due to 2nd exhaust leak within a year), alternator, and PCV valve (less than 3,000 miles ago) were all replaced within the last 6 months.

I noticed better fuel economy when I changed the spark plugs, but this was only for 2 fill up cycles or so, and then back to 'normal' expectations.
 
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SoundEfx

New Member
You have 195K on the car. Don't expect it to act the same every single day.
One of the reasons is the fact that no one could drive the same way every single day on the same road. That mpg is actually good for an auto trans.
 

Muckman

Not a M0derator
Gas mileage generally decreases in the winter for a number of reasons - winter fuel blends, colder temperatures, longer idle periods, precipitation on roads increases tire resistance.
 


Samurai_Blue

Yolo Whippin'
lol at your original comment muckman



1. synthetic oil = better
2. change your o2 sensors
3. we dont have an egr valve
 

K3Ntegra

Member
lol at your original comment muckman



1. synthetic oil = better
2. change your o2 sensors
3. we dont have an egr valve
Thanks for this. I'll check the O2 sensor. These NGKs seem good.


@Muckman, I've never seen the low fuel warning light come on at 245 miles, in the past 6 years I've owned the vehicle.
 


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Samurai_Blue

Yolo Whippin'
Also if you are using non denso or NGK plugs that could affect how things work, as well as non OEM cap and rotor. also thermostat can affect things.
 

K3Ntegra

Member
Are these NGK's considered seconday O2 sensors? And thus has little to anything to do with fuel consumption?

I just got done, replacing the sensor near the oil drain pan, that connects to the exhaust.

I heard the other one is supposedly harder to access and thus much higher labor costs.

Edit:

According to this video, it's the primary sensor, which is great.

A mechanic quoted $40 to replace one of the sensors, and $110 to replace the other one.

I highly recommend using this tool, OEM sensor wrench, if anyone is planning on doing this project. Much better than the stand alone sensor socket. AutoZone rented it out for free.

I read somewhere, a person had to wait a while, before they could experience better fuel economy with their new o2 sensor.
 
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K3Ntegra

Member
I got a third check engine light. After the 2nd check engine light, I disconnected the batter and the 3rd light came on after 300 miles. I though it was because of re-seating the new O2 sensor.

I took it to a mechanic, and he stated that a one of the fuel injectors was bad, according to the code. Quoted 135 for the part and $90 for the labor (less than hour, according to their hourly rate). He suggested I should consider changing all of them.

The symptoms, listed here, seem to make sense.

Any additional heads up, if someone is trying to do this repair them self? Is their minimum quality rating, etc I should pay attention to and such?

The mechanic stated I didn't have to worry about the car stopping in the middle road, but I'm wondering how many miles can I go with the bad injector?

Closest video to my model I can find on accessing them. If anyone knows a better one I'd appreciate it.

I'd like to only replace the one bad fuel injector, since I'm running a bit low on cash. How do I know which one's bad? Or do I look for the one leaking?
 
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K3Ntegra

Member
No he didn't. Since the diagnosis was free, I don't want to 'insult' him and ask for more 'free' information. The light's still on which is good I guess.

The code of the 1st check engine light was p1399. A different mechanic suggested clean the EGR valve then replace catalytic converter if that didn't work. After the 3rd light I told a different mechanic that works there, Integras didn't have EGR valves.

Thanks for the response. I think I'll try to have all 4 injectors replaced. Should I consider the 'CC' size rating? Or something close to OEM will just suffice? I like to rev the car up to 5,500 RPMs daily or so.
 

K3Ntegra

Member
you need oem injectors to be plug and play.I would really just have them cleaned. Theyre probably clogged.
This also means I shouldn't buy these because, the ECU would need to be tuned, as stated in the item description?

According to this video by Scotty Kilmer, old rubber seals should never be reused. Would this apply to G3 Integras?
 
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Samurai_Blue

Yolo Whippin'
you shouldnt reuse a rubber seal that you dont want to replace. if you get your old injectors cleaned they give you new seals
 
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