Right Finally After A Year A Topic About Fixing My Flat Spot

[sphinktar1988]

Right Guna try bullet point this as theres lots of info to fit in and i dont wanna bore you with a massive amount of text

if you read on you will understand why i am scared to put a new cat converter in before my MOT as i worry it will happen again

1.3 2000 X reg sr

the problems started when i had a garage take my centre pipe out of the standard exhaust system

was fine at first but then a 2 or 3 month later my engine management light came on

my car then developed a small flat spot which has got worse over time

then it failed its MOT test on emissions he said they were thru the roof

trying too fix the problem i had the cat taken out and looked at, it was totally melted and useless it got binned as the exhaust centre said it had been over fueled

ive since replaced the whole exhaust system with a powerflow system and is currently decat'd

the flat stop has never changed no matter what has been changed on the car

the flat spot is only when first touching the accelerator and the car feels very sluggish untill in high revs

the only way to pull away is to tap the pedal till the revs build up

now for my MOT i have to put a cat back in and am looking to put an envy sports cat in but i dont want to put this in untill the problem is fixed

as if it breaks the cat again im £300 out of pocket

i heard of a simalar problem on an avensis where the first lamdor sensor had broke meaning the ECU wasnt gettin the required information

wondered if this could have happened due to the centre pipe being removed and cause the engine to overfuel and ruin the cat?

any input is much appriciated cause i really wanna get rid of this once and for all

had the lamdors out the other day but was no good as you cant tell if there broke from looking at them there just pretty black

if it is overfueling how much am i looking at for toyota to put it right?

if theres anymore info needed jst ask ill get it edited ASAP

thanks in advance alex

[compressor mad]

you could do a resistence check across the lamba sensors to see whether they are within specs that would tell you if the car was over fuelling

[sphinktar1988]

eah lol

whats thats mean? and entail?

thanks

[compressor mad]

u will need to get the specs for your car then follow the wire from the sensor up to the plug

then unplug it and take a resistence check from the plug terminals (you will need a multi meter to do it)

[T V O R]

Why have you taken the cat converter off the car?

[sphinktar1988]

well the cat was completely wreaked so i took it out as it wasnt working anymore and had my car decat'd as there are obvious performance benifits from it

its besides the point anyways as im trying to solve the issue with my car as im at the end of my teather with it

[seveer unaek]

Well, if you're at the end of your tether, take it to a GOOD mechanic and get them to have a look at it.

Before that though... Put car back to standard with new lamda sensors as if they are totally black then they are shagged. Make sure all connetions are good (electrical and mechanical) fit a new air filter element, change the oil for good stuff, run some fuel-system cleaner through the tank when you next fill up, re-set ecu completly (remove the connection to it) then give car a good run for 100 miles, yes you're using your fuel and going nowhere, but what you're doing is refreshing the whole system.

Then, if its still knackered, get it to a mechanic. But please, do all that stuff, because from what you've said all that you've done is ***** about with the exhaust.

[T V O R]

What are the performance benefits from having the cat removed?

[sphinktar1988]

seveer - cheers didnt no that they were shagged if they were black got 2 news ones on order will i need to change both or is it just the first one thats important, ill change the oil, airfilers an apexi n thats stayin on cause its unreal thanks for the advice

TVOR- the benifits are increased BHP, more high end power, change in the exhaust tone (all depending on the car) ive noticed a massive benifit from it just wanting to get this problem sorted so i can enjoy the car to the full extent

[seveer unaek]

Usually 1st one that causes errors, but change them both to be sure. If ever you change a section of exhaust with them in its advisable to change the sensors at the same time as any knock or dirt that goes near them can damage them. They're a very sensitive bit of kit. They should last 70k miles though without a single hiccup. Although a Decat will shag the second one pretty sharpish!

[sphinktar1988]

!Removed! the bed lol both ave been in for 121k now so there guna be well shagged

yea the sports cats going in same time as the new sensors and if that doesnt fix it im really lost and skint and wont b able to drive it cause im not wreakin the new cat

ill ave to take it to toyota to have my faults cancelled wont i?

[sphinktar1988]

do faults stay on the ecu after the Battery is disconnected for the 20min period?

[armoredfist2002]

do faults stay on the ecu after the battery is disconnected for the 20min period?

Not usually, as people on here say to disconnect the Battery for 1/2 hour to remove any engine management errors and for the light to go off

[sphinktar1988]

ah i see hmmm

if i take my Battery off for like 10 seconds my error light goes off for 40 mins :S

so basically if i put 2 new lamdor sensors in and reset the ecu? that should put things back to normal

and

if not ill ave to get toyota to cancel the faults / sort the fueling out?

[gar]

ah i see hmmm

if i take my battery off for like 10 seconds my error light goes off for 40 mins :S

so basically if i put 2 new lamdor sensors in and reset the ecu? that should put things back to normal

and

if not ill ave to get toyota to cancel the faults / sort the fueling out?

Hi, although it is not likely in your case, the cat can also get bottom screwed! by constantly driving through high water or by parking in long grass, etc, when hot. These things tend to overheat it and shorten it's life by quite a degree! More noticable on dropped vehicles!!