More noise, less power

[Fin]

I have developed a bit of an issue over the last couple of days...
My car starts perfectly, ticks over smoothly, drives perfectly up to about 3 to 4k rpm.
Then... if I try to drive in an 'energetic and enthusiastic' manner, the engine noise changes and I lose some speed at the top of each gear
To be honest, I actually like the noise, it sounds like a straight through/tuned exhaust  s:D s:D  . What I don't like is the loss of power, never a good sign   s:( s:(  
When not under pressure, revving is clean and crisp.
There is no smoke/steam from the exhaust, unless the weather is cold/wet, then the usual white puffs from an engine with a cat.
I have a slow water leak (can lowered water pressure cause this kind of thing?), but the bottle has never been allowed to run dry. I think it's my rad at the usual bottom left spot.
I had the oil changed as I have done about 5k miles since I got her, slight improvent but still got the problem.
While they had it, I got them to look at the exhaust, but they couldn't find anything wrong with it (they are an exhaust centre, not a Toyota specialist....)
So, to summarise...
1, has anyone come across anything similar?
2, does anyone have any pointers where to look?
3, can anyone recommend a decent garage near me (Tunbridge Wells in Kent)?

[Wabbitkilla]

Preferred possibility is the maf is dirty or faulty.
Next possibility is catalyst or precat failure blocking the exhaust.

First try cleaning the maf and reset the ecu.

[wotugonado]

Have a read of this symptoms sound similar
 l viewtopic.php?f=11&t=43983&p=516063&hilit=blocked+cat#p516063 l
Hopefully its not but may be you could eliminate it anyway.

[Fin]

Hmmm, I've really got to get myself an O2 socket, and soon!!!
Some of those symptoms do sound similar, I was thinking it must be exhaust related somehow. (Or a knackered head)

[Fin]

Well, ya live and learn, dontcha   s:?: :?: s:?:  
Just got back from my local automotive electrician, got him to plug her into his SOLUS machine.
He did a full reset on the ECU,  and my problems seem to have been cured, for the sake of twenty quid  s:bounce: :bounce: s:bounce:  
I thought that using my OBD reader was sufficient to clear down the problems  s:oops: :oops: s:oops:   I don't know if it was because I did something wrong, or because my MAF was so dirty brfore I cleaned it last week, but that seems to have been the root of my troubles   s:D s:D  
So, a message to all the others on here who aren't quite sure what they're doing...
The how-to's on the forum were written by people who know what they're talking about, read them properly!!!

[Joesson]

I believe a lot of the ROC members "wear The Tee shirt" and have got it dirty doing what their writing about!

[redarrow]

A new maf secor is part of my yearly service.

I must admit i need a new/ secoundhand
But vgc standard cat... Pm me got one for sale !

[Fin]

Thanks for the offer, but  I'm off to see an exhaust specialist today. Looking at getting a stainless system made for her  s:bounce: :bounce: s:bounce:

[Fin]

Well, that was a waste of time then  s:( s:(
They talked the talk, but they were worse than useless when I got there  s:flame: :flame: s:flame:  
When I plug in my OBD, and ask for real-time information, it says Catalytic Converter Information Incomplete.
Should my Cat be 'talking' to my ECU?
If they're not talking, does this mean my Cat has failed, and this is where I should be looking? (As well as checking/knocking out if they're still there my Pre-Cats)?
It seems that everywhere I go, they take one look and say 'ooooh, mid-engine.... don't know nuffin' 'bout them, errrrm'.
I can get a new cat locally, I have  an ECP down the road who can supply at a reasonable price. I just don't fancy shelling out that much unless I know that's the problem.

[Wabbitkilla]

Some cars have catalyst heating, our car does not. Obdii is a generic system so it will still look for the data relating to cat heating. Incomplete just means our ecu doesn't support it. You need to monitor the pre catalyst O2 sensor pulse patterns and the post catalyst patterns and compare. Simply though if you don't get a code stating catalyst operating below efficiency then the cat is doing its job. The only way to look for your problem is to get physical and take the O2 sensors out for a look or just take the whole catalyst off for a look.

[andyroo104]

I have an aftermarket cat recently removed if you need to test it and I am also in Kent.

[Fin]

I'm reasonably sure it's a sensor problem really.
I've booked it in On Wednesday, asI'm just working too many hours at the moment.
Thanks for the offer Andyroo, you're not a million miles away, I'll bear that in mind:)

[andyroo104]

No problem just let me know.

[redarrow]

When you say you lose power in gears like how ?

Example
 1st 0 to 30
2nd 30 to 50
3rd 50 to 70
4th 70 to 90
5th 90 to 110

What order does yours go please....


Ps. Afther reading what you have said sounds
Like a hole in the exhuast , know i was told
You can also have fine crack or a seal come apart
From the exhust it self , i was told turn engine on
And use a tissue and place the tissue along the exhuast
To see if any escaping air hit it, if it does that the point
Where the crack is or line fracture ....

Becouse there noise , also check the rubber pipes
Leading to the air box, and also cheek the air box for
Leafs and crap.

Be carefull exhuast get so hot use gloves....

Afther that above only way strip the exhuast
And look at the precat .....

If you take out a o2 sensor left and right your see with a torch
In the hole ,A honey come nest, that the dreadded pre cat that everybody
Dreads , if it brakes apart it can go into the engine
And destroy the car..

The idea is you take the mainifold off ,and
Wack that honey come out both sides with a
Long screwdriver and that
Suppose to stop the precat engine destroying  method
, they say if it not there in the mainifold
Then it can not heart the engine and the one
Cat on the car is  enough to go thu it mot on
It own.

[Fin]

The last thing I did was clean the MAF sensor, so I'm assuming I damaged it somehow. I've ordered a new one, along with an O2 sensor (I've had one ready for a while, so I'll do both). That will give me a chance to check if I still have pre-cats or not (not for long if I have).
I've decided to do it myself, rather than pay someone else.
If I'm lucky, this might be my excuse for a nice new exhaust system  s:D s:D

[Fin]

Hmmmm, OK,  well £400 odd quid later and...
I no longer have Pre-cats, has improved the exhaust sound as well (nice little bonus there  s:) s:)  ), doesn't look like they'd done any damage anywhere in the engine.
I have new O2 sensors, (both Denso) I'll wait and see how they work out ref error problems...
I have a new MAF sensor, the old one wasn't giving a proper reading.
I have a porous sump   s:scared: :scared: s:scared:  (New one Tuesday after Easter).

She is revving fast and easy up to about 4k, then she still isn't right. Just not getting the power through the higher revs  s:( s:(
I'll do a full ECU reset in the morning, my radio was still tuned, so I don't think he did one. But I am working about 20 miles away tonight, so I will be able to disconnect the battery when I get to work, reconnect it in the morning, let her warm up and then take her for a nice long detouring drive in the morning through the lanes. As usual, I hadn't read the section on the reset properly, didn't see the bit about letting the engine warm up before driving off, and then going for a nice long drive without hammering the throttle too hard.
TBH, I'm still not 100% convinced about the CAT itself. I forgot to ask if he had pressure tested the exhaust, as it still feels like an exhaust/back pressure issue. This would explain the drop in power and pick up in noise? Possibly?

[thekickinside]

stupid thought....have you changed the air filter and changed the spark plugs?

[Fin]

Hopefully not a stupid thought at all  s:) s:)
Especially since I'm planning to do exactly that!!!

[Fin]

Ordered a K&N panel filter, and some Denso plugs. Hopefully have them by mid-week. I'm starting to think this is a fuelling/air issue.
2 questions really...
1, does anyone know the correct gap for standard copper plugs?
2, does anyone have the address for a decent psychiatrist? My wife thinks I should sell the car and get a 'normal' one!!!!  s:scared: :scared: s:scared:   s:evil: :evil: s:evil:

[Ardent]

Spark plug type:
DENSO SK16R11
NGK IFR5A11
Spark plug gap, mm (in.):
1.1 (0.043)

[Fin]

Thanks for that.
I'm fairly sure it's a fuel/air problem now. That's what my symptoms seem to bepointing at:
low power,
flat spots,
excessive exhaust noise,
hesitating when throttle pressed,
runs fine on tickover/light throttle pressure.
When the MAF sensor is playing up, am I right in thinking thatit doesn't throw an error code? I ask because I bought a nonOEM MAF. I'm toying with popping to Mr t's and buying an OEM one, if there's a chance that will cure my problem. I'm fairly sure this all started when I tried to clean my old one...
In the good old days, I would have been checking my points/plugs and carb.

[Fin]

OK, latest update, in the hope someone has seen something similar...
New K&N panel filter, done.  s:) s:)  
New Denso spark plugs, done. I did notice a little oil around the tops of a couple of the old Bosch Multi-sparks I removed (I have a very light leak on my cam-cover, but my mechanic said it isn't worth doing). The old plugs were a lovely rich-tea biscuit colour with no evidence of oil contamination.  s:) s:)  
New Denso O2 sensors, done.  s:) s:)  
Original Toyota MAF sensor, properly cleaned and put back (seems to be giving good readings...), done.  s:) s:)  
Pre-Cats removed, exhaust given a thorough check-over at the time, done.  s:) s:)  

Does the ignition timing ever go slightly off on these? Feels almost like I am getting pre-ignition?? I am still getting problems, and it feels like an ignition issue. (In the old days, I would have done the points/capacitor by now). Unfortunately, I am a bit behind the timers with these new-fangled engines (you probably guessed that by now!!)
Where would I find the VVTi? Can I test it? How hard is it to replace? Is this the possible cause of my problems? Do they go wrong very often?I read somewhere on here that it may be the cause if my problems are around the 4000 RPM mark.
I'm wondering if the air/fuel thing is a bit of a red herring, and I should be looking at the ignition side of things...
Oh, and I don't get any fault codes.

[Ardent]

Fin

if you dont mind pm'ing your E
I have 2 very good pdf docs on the vvti

Jason

[Fin]

pm sent, thanks

[Ardent]

pdfs sent