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pgwerner

Just Bought '05 Corolla - Mileage Is Awful!

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Why did you use fuel injector cleaner on a brand new car?

 

 

That's a good question.... Although it is a 2006, I've already managed to put nearly 10,000 miles on my vehicle and have been guilty of purchasing gas that may not have been of the highest quality. Therefore, I used a bottle of injector cleaner to remove any build-up that may have occured to date...

You must drive a lot to have put on 10,000 miles already.

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trap
Ok, I tried checking my ECU this evening by removing my glove box compartment. I did locate the ECU, but I could not identify whether it is made from Denso or Delco. It didnt say on the visible part of the unit, so this weekend im going to literally take off the ECU and check it out that way. To tell you the truth, By comparing what I saw with the picture from the repair manual, mine looks like the delco one :(

Still, I can't be entirely sure yet.

I took some pics too

This is with the glove compartment removed The white "Toyota Denso 5"sticker is for the cabin fan, not the ecu.

My pos camera couldnt focus.. this is supposed to be the ECU located near the bottom

This is underneath the ECU, all it says is "Toyota Computer, engine control" and some numbers.

 

You have Denso. Delco starts with P/N 89666, Denso starts with 89661.

What's your MPG?

AT or MT?

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Ok, I tried checking my ECU this evening by removing my glove box compartment. I did locate the ECU, but I could not identify whether it is made from Denso or Delco. It didnt say on the visible part of the unit, so this weekend im going to literally take off the ECU and check it out that way. To tell you the truth, By comparing what I saw with the picture from the repair manual, mine looks like the delco one :(

Still, I can't be entirely sure yet.

I took some pics too

This is with the glove compartment removed The white "Toyota Denso 5"sticker is for the cabin fan, not the ecu.

My pos camera couldnt focus.. this is supposed to be the ECU located near the bottom

This is underneath the ECU, all it says is "Toyota Computer, engine control" and some numbers.

 

You have Denso. Delco starts with P/N 89666, Denso starts with 89661.

What's your MPG?

AT or MT?

All mine are Denso and start with 89661-.

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Ok, I tried checking my ECU this evening by removing my glove box compartment. I did locate the ECU, but I could not identify whether it is made from Denso or Delco. It didnt say on the visible part of the unit, so this weekend im going to literally take off the ECU and check it out that way. To tell you the truth, By comparing what I saw with the picture from the repair manual, mine looks like the delco one :(

Still, I can't be entirely sure yet.

I took some pics too

This is with the glove compartment removed The white "Toyota Denso 5"sticker is for the cabin fan, not the ecu.

My pos camera couldnt focus.. this is supposed to be the ECU located near the bottom

This is underneath the ECU, all it says is "Toyota Computer, engine control" and some numbers.

 

You have Denso. Delco starts with P/N 89666, Denso starts with 89661.

What's your MPG?

AT or MT?

 

Wow, you just refuted the ecu hypothesis.. thanks for the info. I have auto and I get around 24~25 mpg, half city half highway. Hmm maybe its the gas thats causing worse gas mileage, but the thing is I tried different brand/grade gas and I consistently get low mpg- maybe it has to do more with the region that I live (north east, maryland)

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Ok, I tried checking my ECU this evening by removing my glove box compartment. I did locate the ECU, but I could not identify whether it is made from Denso or Delco. It didnt say on the visible part of the unit, so this weekend im going to literally take off the ECU and check it out that way. To tell you the truth, By comparing what I saw with the picture from the repair manual, mine looks like the delco one :(

Still, I can't be entirely sure yet.

I took some pics too

This is with the glove compartment removed The white "Toyota Denso 5"sticker is for the cabin fan, not the ecu.

My pos camera couldnt focus.. this is supposed to be the ECU located near the bottom

This is underneath the ECU, all it says is "Toyota Computer, engine control" and some numbers.

 

You have Denso. Delco starts with P/N 89666, Denso starts with 89661.

What's your MPG?

AT or MT?

 

Wow, you just refuted the ecu hypothesis.. thanks for the info. I have auto and I get around 24~25 mpg, half city half highway. Hmm maybe its the gas thats causing worse gas mileage, but the thing is I tried different brand/grade gas and I consistently get low mpg- maybe it has to do more with the region that I live (north east, maryland)

I also have auto and am currently getting 29.6 MPG doing almost all highway.

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You must drive a lot to have put on 10,000 miles already.

 

Yes, indeed I do... I average about 300 miles a week just going to/from work, and it seems about once a month we make a trip to visit the soon-to-be inlaws and that's about 500 miles roundtrip... My girl drives a Mustang so needless to say when we go on long trips we take the Corolla for comfort and fuel usage. Mercifully I'll be moving in a couple months to a location that is only a mile from my office, so I won't be racking up near as many miles.

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Ok, I tried checking my ECU this evening by removing my glove box compartment. I did locate the ECU, but I could not identify whether it is made from Denso or Delco. It didnt say on the visible part of the unit, so this weekend im going to literally take off the ECU and check it out that way. To tell you the truth, By comparing what I saw with the picture from the repair manual, mine looks like the delco one :(

Still, I can't be entirely sure yet.

I took some pics too

This is with the glove compartment removed The white "Toyota Denso 5"sticker is for the cabin fan, not the ecu.

My pos camera couldnt focus.. this is supposed to be the ECU located near the bottom

This is underneath the ECU, all it says is "Toyota Computer, engine control" and some numbers.

 

You have Denso. Delco starts with P/N 89666, Denso starts with 89661.

What's your MPG?

AT or MT?

 

Wow, you just refuted the ecu hypothesis.. thanks for the info. I have auto and I get around 24~25 mpg, half city half highway. Hmm maybe its the gas thats causing worse gas mileage, but the thing is I tried different brand/grade gas and I consistently get low mpg- maybe it has to do more with the region that I live (north east, maryland)

 

 

Well, it is more complicated than that. The ECUs have different model numbers, yours is 02C12. For example, I know that Delco made models 02150 (non-reprogramable) and 02154 (reprogramable) in 2003. I don't know about 2005 but in 2003 (based on the sulfur farts TSB I have a copy of) there were 4 versions of software (toyota calls it ECU calibration ID) for MT and 3 versions for AT. This is for Denso. There are 4 additional ones for Delco ECU. The problem could be software-based and not necceserely hardware-based.

 

I believe you have to have toyota diagnostic kit with correct software on card to check your version.

 

I doubt toyota will be willing to disclose this info.

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You must drive a lot to have put on 10,000 miles already.

 

Yes, indeed I do... I average about 300 miles a week just going to/from work, and it seems about once a month we make a trip to visit the soon-to-be inlaws and that's about 500 miles roundtrip... My drives a Mustang so needless to say when we go on long trips we take the Corolla for comfort and fuel usage. Mercifully I'll be moving in a couple months to a location that is only a mile from my office, so I won't be racking up near as many miles.

I drive about 100 miles a day to get back and forth from my new job. That is closer to 500 miles per week. I hope to eventually move closer. It will be nice for you after you move and won't have the long commute.

Maybe your new car will last a little longer.

Edited by Bikeman982

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Ok, I tried checking my ECU this evening by removing my glove box compartment. I did locate the ECU, but I could not identify whether it is made from Denso or Delco. It didnt say on the visible part of the unit, so this weekend im going to literally take off the ECU and check it out that way. To tell you the truth, By comparing what I saw with the picture from the repair manual, mine looks like the delco one :(

Still, I can't be entirely sure yet.

I took some pics too

This is with the glove compartment removed The white "Toyota Denso 5"sticker is for the cabin fan, not the ecu.

My pos camera couldnt focus.. this is supposed to be the ECU located near the bottom

This is underneath the ECU, all it says is "Toyota Computer, engine control" and some numbers.

 

You have Denso. Delco starts with P/N 89666, Denso starts with 89661.

What's your MPG?

AT or MT?

 

Wow, you just refuted the ecu hypothesis.. thanks for the info. I have auto and I get around 24~25 mpg, half city half highway. Hmm maybe its the gas thats causing worse gas mileage, but the thing is I tried different brand/grade gas and I consistently get low mpg- maybe it has to do more with the region that I live (north east, maryland)

 

 

Finally, I checked mine. Very easy, the ECU is located below the glove compartment, visible from underneath.

It is 89666-02154, meaning that it is a reprogrammable model of Delco. The funny thing is that it is actually labeled "Denso, Made in Tennessee". This is contrary to my source from: http://www.autosafety.org/Toyota%2003-04%2...%20Catalyst.pdf

 

Nevertheless, it is different from yours so, the ECU is not the whole story here. Software/firmware? Maybe. However, mine was reflashed to comply with the sulfure fix and I did not see a measurable change in MPG. I did see some change in AT logic with fewer downshifts on mild grades.

 

The bigest jump in MPG I ever saw was a year ago when the dealer went from 10W30 to 5W30 oil. The city MPG went from 27 to 28 MPG. I cleaned MAF at the same time, so not clear what helped.

 

When I find a cheap O2 sensor, I will try a swap. Recently, I replaced O2 sensor in my subaru at 60,000 miles (despite no CEL and good histogram on OBD2 scanner) and the MPG went up 10% (city and hwy).

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I just recomputed my gas mileage for my last tankfull and I got exactly 30 MPG. That is the best I have attained, so far. I use 20W-50W oil, because I drive a long distance at one time and I want the heated engine to run smooth. If I drove city miles or in a colder climate area I would probably use a thinner viscosity oil, such as 5W-30W.

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I've read on Consumer Reports that 2006 corolla LE auto gets 28.6 mpg city/highway combined, 30mpg on XRS mostly highway. Those figures are less than epa estimated mpg, especially LE's gas mileage which doesnt even reach city 30mpg.

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I've read on Consumer Reports that 2006 corolla LE auto gets 28.6 mpg city/highway combined, 30mpg on XRS mostly highway. Those figures are less than epa estimated mpg, especially LE's gas mileage which doesnt even reach city 30mpg.

Doesn't seem very high to me. Anything less than 35-40 MPG gets expensive when you drive a lot of miles and have to spend what is now higher gas prices. What happens when the cost of gas goes really high? Most people will want better mileage than those Toyotas provide.

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yes indeed, those numbers arent high. Interestingly, consumer report said "corolla LE gets budget-pleasing 28.6 mpg", but to me, it sounds like "corolla's a lemon".

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yes indeed, those numbers arent high. Interestingly, consumer report said "corolla LE gets budget-pleasing 28.6 mpg", but to me, it sounds like "corolla's a lemon".

It depends on whose "budget" they are talking about - certainly not mine or the average consumer.

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maybe the consumer report driver drove a corolla with the ECU that gives lower mileage. Or, he was paid to drive such that the mileage was low. Or, he picked the winter gas which reduces the mileage even more. Or, ...

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