: Poor Gas Mileage



werwer2012
01-10-13, 06:43 PM
I have a 1999 catera and I have noticed that over the past month or so the gas mileage is getting really bad. I had it into the garage and they changed the air filter and plugs and it still is bad. I go 50 to 60 klms on a 1/2 a tank of gas and it cost me $32 to fill it up again. Can anyone give me any idea's what else they sholud check. Any help would be greatly appreciated.

Thanks..Greg

JohnJJO
01-11-13, 12:51 AM
Welcome to the club of Low MPG. My cat can go only 240 miles on regular gas . And like 190 on premium. And I'm not flying around. Keeping my idle up to 3000rmp.
OEM New spark plugs.
Air filter, fuel filter
Injectors hand cleaning and multiple time cleaners to the fuel tank was add + seafoam was preformed few times to.
No help.

gvjv3
01-11-13, 02:34 AM
Hello

what you might try is start the car and have someone run the RPM,s up, at the same time go to exhaust pipe and smell the exhaust, if really is strong than your burning rich, (more fuel than needed) The most common problem to this is a bad MAF, I took mine out and bought MAF cleaner, clean it and put it back, took off all the connection to it and but them back on, it work for me, might for you,

werwer2012
01-11-13, 05:07 PM
Thanks for the information. What is an MAF?

MoistCabbage
01-11-13, 06:29 PM
Mass Air Flow sensor.

I'd suspect the FPR (Fuel Pressure Regulator) before the MAF.

nethic
01-11-13, 08:46 PM
how much to replace both those parts ? I get the same issue but I'm almost positive its the o2 sensors (which I have brand new just can't put in since I have no jack )

MoistCabbage
01-11-13, 08:52 PM
Never priced either for a Catera, but FPRs are fairly cheap, MAFs can get expensive.

Why are you replacing the O2 sensors? Is the CEL illuminated? Did you pull the codes?

werwer2012
01-11-13, 09:51 PM
I have heard that you can clean a MAS sensor. Is that something the average person should attempt?

Greg

nethic
01-11-13, 10:11 PM
Never priced either for a Catera, but FPRs are fairly cheap, MAFs can get expensive.

Why are you replacing the O2 sensors? Is the CEL illuminated? Did you pull the codes?

Not yet, my OBDII reader is on the way so I should have the codes pulled soon.

MoistCabbage
01-11-13, 10:29 PM
Yes, you can clean a MAF sensor. Not difficult in any way. Buy some MAF cleaner, remove the sensor, spray it clean, reinstall. If there are any codes for MAF voltage, cleaning it won't do a thing.

If the CEL isn't illuminated, the O2 sensors are fine.

werwer2012
01-12-13, 09:27 AM
Thanks for the information...Greg

JohnJJO
01-12-13, 01:48 PM
Pass month was monitoring my mpg:
2000 Cadillac Caters Sport with 153k miles, tire pressure was monitoring. Had full trunk of my tools, include prof. heavy jack. Newer air and fuel filter. OEM spark plug with approx. 20k on them. Engine oil Castrol GTX 5w-30 had approx. 3k of use when I started my mpg monitoring. Car was treated with Lucas and Seafoam frequently in a pass. During this time had no passengers and only me drove the vehicle.
Results:
Regular 87 - 16 mpg
Premium 93 - 13.1 mpg

Both time used Costco gas. Vehicle was driven in city only, in general keeped my foot on up to 3000rpm. But some time had to reached to 5000. I'm not crazy driver.
I did saw the differents between 87 and 93 gas. Premium gave me better power and kind of stable. But It was not worst to lose 50 miles of driveble distance by using premium 93 gas....
Any comments?......

gvjv3
01-12-13, 02:31 PM
umm, something up? I get better mileage with Premium than Regular, if I use Regular I get poor mileage and the engine pins, I adv about 25 mpg

102330

JohnJJO
01-17-13, 10:55 PM
wow so what to do now?.......
since i been have this car used regular

cateralover1209
01-19-13, 09:46 PM
Well in my 2001 catera sport black i been having suspicions of the coolant bridge sensors theres two sensors on the coolant bridge.One is a single wire plugged on top of it and this sensor gives you the reading on your dash.the other one is a coolant temp sensor that tells your ECU(electronic control module) when it has reached closed loop so if that sensor is faulty youre runnig open loop for a longer period of time ,witch will kill youre gas mileage try looking into those sensors there only like 12$ each and try cleaning the ccv(cranck case ventilator )

CadillacManny
03-05-13, 11:15 AM
That's horrible I get 300miles a tank and I use the required 93

JohnJJO
03-05-13, 10:24 PM
Guys I did big job today, replaced thermostat, temperature sensor, thermostat sender sensor, fuel pressure regulator and engine oil cooler. I did all video recording and will post them on youtube soon. U can find few videos on YouTube regarding door noise and side mirrors stuck issues. Just type in YouTube search box: Catera door noise or catera window switch for second video. Also three more video coming soon regarding radio removal procedure, climate control bulb replacements and how to remove rubber covering on interior trim. Next week I'm hoping to find time and replace front struts, control arm bushing, front and rear stabilizer bar bushing and links. Video will be done also and will go on YouTube :)

JohnJJO
03-16-13, 08:56 AM
i replaced temp. sensor, temp. sender sensor on coolant bridge, while i was there i decide to replaced thermostat and oil cooler due to external leak. MY MPG dind went up !!!!!! im getting same 13-16mpg....... + just realized that since pass year (after my friend told me) car feel likes not going no where, feels like i have around 100 hp - 100 torch...... no cheack engin light..... rpm 600-630 on warm.

MoistCabbage
03-16-13, 10:25 AM
Please stop double posting and hijacking threads.

As posted to you in another thread: Start your own thread, pull your codes, post them and their definitions.

JohnJJO
03-16-13, 12:05 PM
What are u talking about . That'd like almost my thread... Look how many respond I had on that thread. That's my add on to it! Regarding of replacements of temp sensors. That was recommended. That didn't work out.

MoistCabbage
03-16-13, 12:26 PM
Oh, I see, you hijacked it in January, guess that makes it your thread...

This is a perfect example why you shouldn't do it in the first place. Information gets missed, and it takes longer for you to get an answer:

Since I'm just seeing your above post on this page I'm assuming it's your first post on the problem. There's more information on YOUR problem earlier in the thread, but since it's not your thread, I had no reason to go one page, and two months back, looking for your posts.

As for replacing the temp sensors, nobody told you to do that. A member posted that he was suspicious of his. Unless you had codes pointing to a bad temperature sensor, or that the engine wasn't reaching normal operating temperature, they were fine.

Once again, start a thread, and start from the beginning. Describe the problem, PULL YOUR CODES, LIST THEM AND THEIR DEFINITIONS.

kaustein
03-16-13, 01:05 PM
I always used reg. Road trips via cruise 25iish. Around town, maybe 20 at best!

zenanick
04-18-14, 02:03 PM
I have a 1999 catera and I have noticed that over the past month or so the gas mileage is getting really bad. I had it into the garage and they changed the air filter and plugs and it still is bad. I go 50 to 60 klms on a 1/2 a tank of gas and it cost me $32 to fill it up again. Can anyone give me any idea's what else they sholud check. Any help would be greatly appreciated.

Thanks..Greg

New search

JohnJJO
04-18-14, 07:02 PM
Regular..... never.