Loss Of Power

[wpowell]

While I was out driving on Sunday, after a few short sharpe accellerations I noticed a slight miss fire between 4000 to 5000 RPM. I continued to my destination for the next 10 miles at around 70 MPH which is below the RPM where the miss fire occured without no further problem noticed..

On the return journey I took the car to between 4000 to 5000 RPM range for short distances again and had the same miss fire occur, however, the miss fire and lack of power was now more noticable. If I put the accelerator pedal fully to the floor I could not get the engine to rev no more than 4000 RPM with a rapid miss fire occuring. From there I limped the car home for the next couple of miles at slow speed around 30 MPH.

Can anyone direct me to what the problem could be. I have not yet got an OBDII reader but I will be definitley ordering one first thing in the morning.

Regards

Will

[mike_sekinger]

You may have a problem with your HT leads or coil packs. It sounds more like HT leads given the association with load and higher revs.

When you get your OBDII reader, the codes (Po 300-306) will indicate which cylinder is misfiring and you can focus your check on those leads, plugs etc.

You should definately avoid revving the engine as you can damage your CATs if the emissions rise dramatically. There are some other misfire codes that will be logged if you

Edited April 24, 2007 by mike_sekinger

[Zhastaph]

Yup, i'd agree coil packs or ht leads.

One thing I would add is that i've had the same problems in the past with no error codes logged, i believe that it's only the US models that log stuff like this.

===

If you're planning on looking at it yourself what you need to do is remove both spark plug covers then with the engine running carefully remove each HT lead and lift it just far enough away from the spark plug so that you can hear it cracking. You will generally find that the cylinders that misfire also dont crack when there's a gap between the lead and plug - or sound audibly weaker. Also, because of the way the spark is generated you should find that misfiring cylinders will be in pairs rather than restricted to a single cylinder.

Obviously try this first with the engine off to be sure you know what you're doing, and make sure you pull the lead by the rubber boot around it and not from the actually lead itself or you will risk damaging it. And make sure that when you refit them you press them down hard so that they give a click, else they may just be resting on the plug.

[Rob]

How long have the plugs been in there? Maybe time for new ones (cheaper to try this first before forking out for new ht leads?)

[wpowell]

You may have a problem with your HT leads or coil packs. It sounds more like HT leads given the association with load and higher revs.

When you get your OBDII reader, the codes (Po 300-306) will indicate which cylinder is misfiring and you can focus your check on those leads, plugs etc.

You should definately avoid revving the engine as you can damage your CATs if the emissions rise dramatically. There are some other misfire codes that will be logged if you

[snuffy]

Will

I used to find my pipes got quite sooty as well so that may just be a coincedence.

Adrian

[Zhastaph]

I would like to point out that when the engine was cold the loss in power and miss fire

tbh that still kinda sticks with being HT leads or coil pack, they start that way but before long begin affecting the car whether hot or cold.

[wpowell]

You may have a problem with your HT leads or coil packs. It sounds more like HT leads given the association with load and higher revs.

When you get your OBDII reader, the codes (Po 300-306) will indicate which cylinder is misfiring and you can focus your check on those leads, plugs etc.

You should definately avoid revving the engine as you can damage your CATs if the emissions rise dramatically. There are some other misfire codes that will be logged if you

[oneshot]

Just a thought

I had similar symptoms - no power and spluttering couldn't get above 4000rpm and no error codes logged. Turned out to be the cats that had collapsed. I suppose you could remove your cats to check this.

[mike_sekinger]

If you don

[wpowell]

Hi All,

Just to keep you posted on my recent problem of loss of power. After checking many of the suggestions from the forum that you all offered, I finally tracked the problem down to being the R/H (Drivers side) cat that had disintegrated and was blocking the flow of exhaust gases. I've removed the rest of the ceramic cat from inside of the pipe so to keep me mobile until I purchase a pair of new sport cats.

Any suggestions are welcome on which cats to purchase and where from? PNM are getting some in next week for

[matk]

Will

Just in case Dave doesn't catch up on this I'm pretty sure he was strongly recommended not to drive his car in this condition as further unseen fragments of the knackered Cat could be drawn into all manner of things internally.

Just thought you should check this out? Any others want to comment?

[oneshot]

Mat

Quite right I was told not to drive the car since it's possible for fragments of the disintegrated cat to be pulled back into the turbo which could subsequently be damaged and then bits of that end up in your engine causing major problems.

[andyblackman777]

Will,

I had the same problem , it was both cats, i removed all the broken material and ran the car for a year like it. I don't think that it is very likely that bits of cat would go into the turbo, it would have happened allready if that was the case and there would be a load of tubo failures due to this because the standard cats allways break up.

I have the 100cell PNM cats they just passed the mot after i revved the engine at 3000 rpm for 5mins to get them hot!

cheers Andy

[actwon]

Mat

Quite right I was told not to drive the car since it's possible for fragments of the disintegrated cat to be pulled back into the turbo which could subsequently be damaged and then bits of that end up in your engine causing major problems.

Although possible, highly unlikely. The reason being is that the cat sits on the exhaust side of the turbos, which pushes the air through the exhaust system. Although there is a little suction once the throttle is closed (depends on how much pressure was built up in the entire system), there isn't enough to pull particles from the cat, up to the exhaust manifold and through the exhaust side of the turbo. If you have BOVs there is, even, a smaller chance of this happening.

It is likely that if there is debris, it will be pushed out before anything happens. If you're that concerned, pull the cats and run the car without them for a short period of time (just let the car idle with a few blips of the throttle). You CEL light will come on, because you have disconnected the O2 sensors. After that, shake out your cats, re-install and clear your CEL. You should be fine.

Oh, you may want to take out your boot, as the flow of exhaust air will change and be directed straight at your boot and could melt or malform it. Also, keep the rear decklid open so that the exhaust air has a place to go. Just my $.02 or

[cweeden]

I also had a CAT collapse on me while I drove out to the Nurgurgring once and to fix it I drilled out both CATs with a long masonry drill to ensure they were balanced. It was very painful to destoy a fully working CAT but I was able to have a great weekend on the circuit and many months of driving without any ill effects after this 'upgrade'. I did have a Red ECU from Marcus otherwise the standard ECU will complain about the lack of the CATs and put you in a limp home mode I believe.

I like the Hanger 111 approach although I couldn't find their CAT replacement product on their website you can see it on LEWs News page from a while back about 3/4 down the page...

http://www.lotusespritworld.com/Old%20News/news_Nov05.html

I have no expereince or ties with Hangar 111, I just like the idea of being able to bolt in and out a CAT bypass pipe.

cheers

-Chris

[talon]

I am also getting the P0442 as well as a misfire warning from the scanner. Car seems to run fine, but it's got a definite lag at upper RPMS...

[MGFCrasher]

When I first got mine,it would not pul above 4500rpm under load.This turned out to be both cats blocking and disintigrating.

Had the whole exhaust replaced with a bespoke stainless system with bypass pipes and it ran faultlessly.Put the 200 cell race cats in cats for the MOT and I noticed a very slight hesitation at higher revs.My car also developed an intermittant hesitation at about 5000 revs which I think was possibly the Coil packs. I replaced the plugs and leads and it was better as there was water in the plug holes from condensation.......I got a spare coil pack which went loose with the car as I didnt feel the problem was bad enough to affect the enjoyment, but I also wondered whether if I changed to the bypass pipse again whether the problem would go away ?

Just a note;At the time I phoned PNM and asked for some new leads and the advice I got was that very rarely is it leads but he sells a lot of coil packs...

just advice I got ,take it or leave it but I just thought Iwould pass it on.

Anyway it cant be that bad ,the new owner had it on the rollers a few days after he got it and got 409 bhp.Now I gave up believing rolling road figures a long time ago but given that all it had was itg filters ,new wastegates and a nice exhaust thats not bad...

Edited January 10, 2008 by MGFCrasher

[talon]

Is there any surefire way to tell if the cat(s) are bad? How about the coil packs?

[MGFCrasher]

My experience with the cats will be quite a noticeable drop off in power above 4 - 5k revs.Like hitting a big net!!! When I floored it to try and clear it I also got some smoke out of the engine cover.I suppose because the exhaust was effectively blocked!!

Both mine were shot, and in other words you will really notice it !!!. I should add,I stopped driving it straight away and had a full new system built...

Plugs leads or coil packs with show up as more of an intermittant and sometimes minor hesitation.Mine didnt throw up any fault codes but just felt hesitant under low throttle conditions like cruising in 5 th at 70-80mph.The coil pack will probably break down over a period of time ,hardly noticeable at first.

You have probably already done it but Iwould first change the plugs and dry out the plug holes thoroughly.Inspect the leads.and seal the plug covers when you are absolutely sure there is no moisture left.

Rich

Edited January 10, 2008 by MGFCrasher

[talon]

You think a bum coil pack would be enough to throw the battery light on? It's on all the time although I have brand new battery and it doesn't seem to be the alternator...

[MGFCrasher]

Hi Russ,

I would check the Alternator again.Mine went and the car did all sorts of strange things in the hours before,like misfiring etc...

Just seems worth a shot if the battery hasn't cured your charging light....

I don't want to guess but I have never heard of a coil pack setting off the IGN battery light.It would trow the CEL and might bring up a fault code but not the other one.

Rich

[Pred247]

Talon,

Don't think I'm taking the p1ss, but are you 100% sure it's the battery light, and not the radiator light?

I know it sounds daft, but I've heard of people mixing them up before. They are both red, and look alike.

Just a thought.

John

[talon]

No - it's definitely the battery light. I've already had to deal with the radiator light coming on

[cweeden]

Is there any surefire way to tell if the cat(s) are bad? How about the coil packs?

It depends how bad it is and where the failure has occured. If the whole cat has collapsed then you can see it if you remove the rear exhaust box and shine a torch inside. However the standard cat pipes have two parts internally. You can see the change in outer diameter of the pipe. In my experience the primary cat is the one that fails first (this is the only part that has failed for me and I have had a few go). In this case the secondary cat will look fine and there is no obvious visual sign of the failure. With the back box still off you can gentle thump the cat and listen to see if anything is rattling inside. For a collapsed cat to block the pipe and cause your symptoms it has to become loose and rotate so it should rattle a little at least.

I still have my money on it being a cat failure.

Good luck

cheers

-Chris