2001 Buick Century 3.1 66k miles, Very sluggish

[bigboi407]

No power after 1st when floored, happens most times but not all the time.......sounds like ATF issues. Considering a rattling, maybe bad input shaft? idk

But I do know the "sucking" sound when floored is interesting to note.....Reasoning that any leak should be heard more so under a vacuum, not wot where the manifold pressure is almost ambient.

I wonder if you are hearing the exhaust being forced out small passages from a clogged cat or, god forbid, teenagers shoving apples up the tail pipe.

Thats exactly what i was guessing today as i drove it around and the problem seems to worsen, we live in FL nothing about emissions here, whas the cheapest way i can fix her exhuast problem? AZ wants $275 for a cat and a guy on ebay wants $219,

on a side note, the crx i used to drive that i pulled the motor from came with an after market carb, the people that put it on didnt gut the cat out which is right below the exhaust manifold, i always noticed the carb when revved high would vent gas fumes back to the filter, so i found this info out later while building the new engine for my civic that the cats MUST be gutted to run the carb i run... i gutted the cat & Welded the EGR return everything is just perfect now... carb doesnt spit out fumes

i seen a 1991 Buick Lesabre Custom today... i want one i miss my buick, it was much faster than this century, i remember goin up against like a 2005+ maxima, 0-50mph from a green light, i let him go, i told her to sit back in her seat, punched it to the floor the back end went down and i shot off like a rocket past the maxima, until 50mph then i turned, i got this sucker for free had 45k miles when i got it

[Merc6]

All depends on how the car is maintained. On the freeway* my 109K L82 pulls away from same body style N/A 3800 Buick Regals. I haven't done the LA1 Throttle body or UIM/LIM swap yet either. That's all sitting in the garage for the summer.


*Wasn't a street race but quite a few a$$hats not wanting to be passed up by a possibly slow Centry driver.

[bigboi407]

i was talking to someone and i guess i cannot run it without the cat due to the 2nd o2 sensor or something of that nature, is this true?

i did notice the car runs perfectly fine until a certain point then i hear the noises and it doesnt wanna go anywhere, also runs much hotter than it used to, you guys said that something would have had to clog the cat, well her map sensor was bad for Months before i changed it, could that have clogged the cat? were gonna change the fuel pump anyways considering it was $50 and the fuel filter it had before was clogged up

Can i use the magnaflow cat? shes gonna buy a cat next week

When i dropped the transmission pan the magnet had alot of metal built up on it, a bit too much for 68k miles and being opened once already, you guys think i should hunt for a transmission? i myself dont like A/T's thats why i dont own a buick ATM

[Fireball]

i was talking to someone and i guess i cannot run it without the cat due to the 2nd o2 sensor or something of that nature, is this true?

i did notice the car runs perfectly fine until a certain point then i hear the noises and it doesnt wanna go anywhere, also runs much hotter than it used to, you guys said that something would have had to clog the cat, well her map sensor was bad for Months before i changed it, could that have clogged the cat? were gonna change the fuel pump anyways considering it was $50 and the fuel filter it had before was clogged up

Can i use the magnaflow cat? shes gonna buy a cat next week

When i dropped the transmission pan the magnet had alot of metal built up on it, a bit too much for 68k miles and being opened once already, you guys think i should hunt for a transmission? i myself dont like A/T's thats why i dont own a buick ATM

Dude, that clicking in the first vid sounded almost like the egr! There was a video of a guy here testing the valves with a battery but I can't find them...

http://www.youtube.com/watch?v=hpB6CELWYhQ

There are a bunch of vids on youtube, I'm not saying this is your problem, but if it hasn't been checked it may be a good idea to make sure the passages are clear?

[TGP37]

You could try unbolting the cat and visually look inside with a flash light. When cool of course.

[bigboi407]

You could try unbolting the cat and visually look inside with a flash light. When cool of course.

she did drive the car with a bad map sensor for quite some time so im guessing the excess fuel caused the cat to fail... im gonna change the fuel pump Anyways, cause she bought one so that will be done next... and should i go with the magnaflow or get a different cat?

its still throwing a cyl 1 misfire but doesnt do it all the time, new wires and new plugs, i could try moving the coil pack over see if it follows, but someone was telling me depend on how clogged the cat is, it could be causing ALL these problems

[TGP37]

Depending on how the MAP failed, yes it can cause a rich condition. But the PCM has a catalytic over temp setting that controls max AFR per airflow mass. Not sure how a MAP failure would play into that. Cat protection is coolant temp based. I suppose it is possible to run too rich while having a normal ECT.


If you really do suspect the car driving extra rich for a long period, checking the CAT is a good idea.

No need for performance cats on a stock dd. Plus the cat has a part in muffling the exhaust. A smaller CAT may be a little cheaper, but they are a little more raspy sounding too.

[bigboi407]

Depending on how the MAP failed, yes it can cause a rich condition. But the PCM has a catalytic over temp setting that controls max AFR per airflow mass. Not sure how a MAP failure would play into that. Cat protection is coolant temp based. I suppose it is possible to run too rich while having a normal ECT.


If you really do suspect the car driving extra rich for a long period, checking the CAT is a good idea.

No need for performance cats on a stock dd. Plus the cat has a part in muffling the exhaust. A smaller CAT may be a little cheaper, but they are a little more raspy sounding too.

im sure she wouldnt mind any noise difference, neither would i, i can get the magnaflow for $170, which is about $45-80 cheaper than all the other ones i seen, AZ wants $245 for one, too much $$$ for a cat, imo

[TGP37]

They are expensive for an exhaust part.

[bob442]

If you get a magnaflow cat that have one with an o2 bung in it for the sensor. Also, before you waste time and money get a info red sensor and read how hot that cat is getting after a drive, that will tell you if it's clogged. Other wise you could have slipping bands or and clutches


Sent from my iPhone using my iPhone at work cuz I have nothing to do

[bigboi407]

If you get a magnaflow cat that have one with an o2 bung in it for the sensor. Also, before you waste time and money get a info red sensor and read how hot that cat is getting after a drive, that will tell you if it's clogged. Other wise you could have slipping bands or and clutches


Sent from my iPhone using my iPhone at work cuz I have nothing to do

no couldnt be the tranny causing this, you gotta drive the car to see what i mean, if its the transmission.......... id be suprised, seems to be a pressure problem in the engine as for the temp of the cat, i dont have a thing to take the temp, so thats out the pic....

IT WILL NOT ACT UP while in park.... only when in drive and about 30 seconds after taking off, the magnaflow cat does have an 02 bung after the cat very close to the connection

Where do i get a Throttle body gasket? AZ doesnt have one and id like to take the TB out to check the EGR return

like you were saying TGP, maybe the noises im hearing is pressure built up, i showed pics of the connections, dont know of any other connections that could cause a random leak only in Drive..... So what we got left is exhaust problem or Gas pressure problem.

i dont have a gas pressure guage, or a temp tester....... (My dad is the Riggus Master and doesnt believe in feeler guages, compression testers, or doing anything right...)which makes this more difficult for me... as for sockets wrenches and such, when you need a 14mm you will find nothint but 5/8" sockets, but when you need a 5/8" you find 14mm sockets

[bob442]

well for 10$ you could buy a infrared temp reader....

when my CAT went at 80km on my car, it sounded like it was sucking air in somewhere on the intake, the intake side was very loud, and the exhaust note was really really quiet.

This is an expensive model:

http://www.harborfreight.com/non-contact-laser-thermometer-96451.html

i know they have them for 10-15$ and if you ask around, someone always has one.

[bigboi407]

well for 10$ you could buy a infrared temp reader....

when my CAT went at 80km on my car, it sounded like it was sucking air in somewhere on the intake, the intake side was very loud, and the exhaust note was really really quiet.

This is an expensive model:

http://www.harborfreight.com/non-contact-laser-thermometer-96451.html

i know they have them for 10-15$ and if you ask around, someone always has one.

Well guys, it is DEFF the cat..... today i figured id hit the gas in Park.... and it FINALLY started to bog down, id attempted this before and it would max out, but now the engine bogs down and i got a good whif of some Rotten stench from the exhaust

it keeps throwing codes for EGR and Cyl 1 misfire, the guy @ AZ said hes betting the map sensor being bad for so long killed the cat, he recommended getting a cat then clear the codes if they come back and if the engine isnt running as it should, then something is Really wrong, but hes thinking the same thing like i am, the cat is causing all the pressure to go backwards @ times which is why the car is doing everything its doing...... In Theory that is ^....

When the CEL/Service light comes on does the Car get worse gas milage than when no code is present? someone one time was tellin me that the Computer runs in a different mode when a code is present causing it to run rich, was this guy full of it? or is that what happens?

[TGP37]

I'll tell you something........it could be the fuel pump. I had a pump go bad once, it didn't express symptoms until there was load on the engine. Because the pump was capable of providing fuel at idle and mild cruise. It only acted up when more load was applied. And it had a terrible exhaust odor.

In park, I could floor it, let it hit the RPM limiter a few times and THEN after a few seconds the fuel pressure got too low and it bogged down.

Some codes will cause a "Limp Home" mode. Some codes will tell the PCM to use a default table instead of the sensor. Either will cause a richer fueling condition, for engine safety reasons. Especially if the check engine light is blinking. A blinking code means STOP operating immediately.

Before you buy a cat, test your fuel pressure under load. Seriously, bad pumps can act normal until you really step on the throttle. Most cases the car will run lean which could be the cause of your cyl1 misfire.


If you are up for it, unplug the fuel filter and guide the line from the pump into a clean container. Have a friend insert a jumper wire across the fuel pump relay (keeps the pump on) and measure how much fuel is pumped.

With a BSFC of 0.5 (rough average for NA), your car needs 90 lbs of fuel to make 180 HP for 1 hour. A gallon is approx 6.34 lbs so your pump should not fall below 14.2 gal/hr

So, your pump should push 1 gallon in 4.2 minutes, no less. Or, 1 cup of fuel in 15 seconds.

If you don't get 1 cup in 15 seconds time, chances are the pump is on its way out. A proper operating pump will easily exceed those measurements.

[bigboi407]

I'll tell you something........it could be the fuel pump. I had a pump go bad once, it didn't express symptoms until there was load on the engine. Because the pump was capable of providing fuel at idle and mild cruise. It only acted up when more load was applied. And it had a terrible exhaust odor.

In park, I could floor it, let it hit the RPM limiter a few times and THEN after a few seconds the fuel pressure got too low and it bogged down.

Some codes will cause a "Limp Home" mode. Some codes will tell the PCM to use a default table instead of the sensor. Either will cause a richer fueling condition, for engine safety reasons. Especially if the check engine light is blinking. A blinking code means STOP operating immediately.

Before you buy a cat, test your fuel pressure under load. Seriously, bad pumps can act normal until you really step on the throttle. Most cases the car will run lean which could be the cause of your cyl1 misfire.


If you are up for it, unplug the fuel filter and guide the line from the pump into a clean container. Have a friend insert a jumper wire across the fuel pump relay (keeps the pump on) and measure how much fuel is pumped.

With a BSFC of 0.5 (rough average for NA), your car needs 90 lbs of fuel to make 180 HP for 1 hour. A gallon is approx 6.34 lbs so your pump should not fall below 14.2 gal/hr

So, your pump should push 1 gallon in 4.2 minutes, no less. Or, 1 cup of fuel in 15 seconds.

If you don't get 1 cup in 15 seconds time, chances are the pump is on its way out. A proper operating pump will easily exceed those measurements.

She already bought a fuel pump so ill put it in before ordering the cat if the pump doesnt fix the issue,

i dont think the fuel pump would cause egr code and all the air i hear in the intake, and if you let the engine kick down and rev over it makes some knock noises, which dont sound too good AT ALL, i dont know what that is


is there an access panel under the backseat or do i need to drop the tank like i did in my 91 buick?