Cats holding heat- decrease in mpg's?
#1
Cats holding heat- decrease in mpg's?
hey all,
firstly, truck details... 2002 4x4 SOHC AUTO
so i have noticed over a good amount of time now that my cats are holding heat...alot more than normal. i have knocked the last one out(the one without an 02) but im certain its not the issue. i have been getting less than great mileage out of it lately, been pulling about 210-230 miles to a tank, usually get a better read out than that lol. i pulled plugs today and checked, all seem to be just fine, but will be getting replaced fairly soon, so no un burnt fuel in the cats, and im not losing any oil...so its not being burnt either... that said. im at a loss of ideas.
post up your ideas and thoughts.
thanks guys
firstly, truck details... 2002 4x4 SOHC AUTO
so i have noticed over a good amount of time now that my cats are holding heat...alot more than normal. i have knocked the last one out(the one without an 02) but im certain its not the issue. i have been getting less than great mileage out of it lately, been pulling about 210-230 miles to a tank, usually get a better read out than that lol. i pulled plugs today and checked, all seem to be just fine, but will be getting replaced fairly soon, so no un burnt fuel in the cats, and im not losing any oil...so its not being burnt either... that said. im at a loss of ideas.
post up your ideas and thoughts.
thanks guys
#6
any other ideas?
#7
#11
thats what i would guess too... as for knowing its hotter... you can smell heat. i thought it was my trans for a while, but i checked that out. i was out cruising the mtns one day, and stopped and checked it out more (right after i checked the trans, checking on it) and could feel the high heat coming form it. more than the other
#13
#14
#15
The only thing that can cause the cats to go bad is excessive fuel being dumped into them, making them overheat and either blow up or melt down and clog.
If there is no CEL, I would start by scanning it for any pending codes. Failing that, I'd suspect an upstream O2 sensor starting to fail, or react slowly (usually sets a code).
How many miles are on the vehicle?
If there is no CEL, I would start by scanning it for any pending codes. Failing that, I'd suspect an upstream O2 sensor starting to fail, or react slowly (usually sets a code).
How many miles are on the vehicle?
#16
The only thing that can cause the cats to go bad is excessive fuel being dumped into them, making them overheat and either blow up or melt down and clog.
If there is no CEL, I would start by scanning it for any pending codes. Failing that, I'd suspect an upstream O2 sensor starting to fail, or react slowly (usually sets a code).
How many miles are on the vehicle?
If there is no CEL, I would start by scanning it for any pending codes. Failing that, I'd suspect an upstream O2 sensor starting to fail, or react slowly (usually sets a code).
How many miles are on the vehicle?
im still slightly stumped
#17
If you drove it for awhile with that vacuum leak, it can roast the cats.
It will either melt down and clog up, making it nigh impossible to get over 30MPH, or blow out and start rattling. I have seen the catalyst get into the muffler, making it necessary to replace that as well.
I'd wait until it does one of those two things, as there's no need to replace it while it is still functioning.
It will either melt down and clog up, making it nigh impossible to get over 30MPH, or blow out and start rattling. I have seen the catalyst get into the muffler, making it necessary to replace that as well.
I'd wait until it does one of those two things, as there's no need to replace it while it is still functioning.
#18
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Yeah, but he has a new (to him) muffler.
I've felt the heat coming off of his Cat's, and they get HOT. like, way hotter than mine ever did. My mom's van had a similar problem a while ago, and I think it's prettymuch gone away on its own now. but it never effected her mileage. (also have to remember that were talking apples and oranges here. Just tossing stuff out.)
On the flip side, Zach has a point with "If the cats are clogged, wouldn't the engine run rougher?" Also I'd think that there would be a lack of power, which there definitely is not...
Dan, maybe go through and inspect all the air hoses, and run some injector cleaner through it.
Could it be running slightly rich? Not rich enough to have the exhaust smell like gas, but rich enough that not all of the gas is being burnt in the cylinder, so it's burning up in the Cats, which would make them hotter. That would also effect your mileage.
I've felt the heat coming off of his Cat's, and they get HOT. like, way hotter than mine ever did. My mom's van had a similar problem a while ago, and I think it's prettymuch gone away on its own now. but it never effected her mileage. (also have to remember that were talking apples and oranges here. Just tossing stuff out.)
On the flip side, Zach has a point with "If the cats are clogged, wouldn't the engine run rougher?" Also I'd think that there would be a lack of power, which there definitely is not...
Dan, maybe go through and inspect all the air hoses, and run some injector cleaner through it.
Could it be running slightly rich? Not rich enough to have the exhaust smell like gas, but rich enough that not all of the gas is being burnt in the cylinder, so it's burning up in the Cats, which would make them hotter. That would also effect your mileage.
#22
O2s, my favorite...
I've seen them fail completely with no codes, the heater codes seem fairly reliable, but not the "O2 failed" - usually these go at 50K (getting slow), that being said, I've got 135K on the OEM piece in my Focus that is just fine (a little slow, but good). I see more Bosch failures than Motocraft.
Hot cats is usually feul dumping as Murphy pointed out.
One customer got 3 $29 Bosch O2's from FeeBay (one at a time!) and all 3 were bad with NO codes (STFT and LTFT ROCK solid at "1") - put in a $75 OEM Motorcraft and problems were all solved. Good times...
I've seen them fail completely with no codes, the heater codes seem fairly reliable, but not the "O2 failed" - usually these go at 50K (getting slow), that being said, I've got 135K on the OEM piece in my Focus that is just fine (a little slow, but good). I see more Bosch failures than Motocraft.
Hot cats is usually feul dumping as Murphy pointed out.
One customer got 3 $29 Bosch O2's from FeeBay (one at a time!) and all 3 were bad with NO codes (STFT and LTFT ROCK solid at "1") - put in a $75 OEM Motorcraft and problems were all solved. Good times...
#23
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O2s, my favorite...
I've seen them fail completely with no codes, the heater codes seem fairly reliable, but not the "O2 failed" - usually these go at 50K (getting slow), that being said, I've got 135K on the OEM piece in my Focus that is just fine (a little slow, but good). I see more Bosch failures than Motocraft.
Hot cats is usually feul dumping as Murphy pointed out.
One customer got 3 $29 Bosch O2's from FeeBay (one at a time!) and all 3 were bad with NO codes (STFT and LTFT ROCK solid at "1") - put in a $75 OEM Motorcraft and problems were all solved. Good times...
I've seen them fail completely with no codes, the heater codes seem fairly reliable, but not the "O2 failed" - usually these go at 50K (getting slow), that being said, I've got 135K on the OEM piece in my Focus that is just fine (a little slow, but good). I see more Bosch failures than Motocraft.
Hot cats is usually feul dumping as Murphy pointed out.
One customer got 3 $29 Bosch O2's from FeeBay (one at a time!) and all 3 were bad with NO codes (STFT and LTFT ROCK solid at "1") - put in a $75 OEM Motorcraft and problems were all solved. Good times...
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