Problem With VX220, P0420 Code and Blowing Sounds

Steve_T

I’ve been having some trouble with my VX220 over the last couple of weeks, its been spitting out the P0420 error code which relates to ‘Catalyst System Efficiency Below Threshold (Bank 1)’. I’ve used my code reader to reset this code and if keeps coming back so obviously something must be up.

The exhaust system is standard, the car was registered in Jan 2001 (Build number 170, so one of the earlier cars built) and is approaching 50k miles.

The other day I went to overtake a car on a country road in third gear, had a brown pants moment when the car seemed to loose all power, it bogged down with a sort of blowing sound.

Reading through previous posts on VX220.org I’ve come up with a list of what I think might be wrong;

Lambda sensors needs replacing (pre and post CAT to make sure)
CAT needs to be replaced
Possible crack in the manifold

The car was recently MOT’d and it did take about 15 minutes of fiddling to get it through the emissions test, the tester did mention that he thought the cat could be on the way out but couldn’t be sure.

Also if it does turn out to be dodgy lambda sensors, are the third party non Vaux items on ebay up to scratch?

I don’t really want to want to spend ££££’s on new sensors etc if they aren’t gonna solve the problem!!

So does anyone have any ideas or had a similar experience?

MikeS

i got a spare simulator than came off a vx220 if your interested for your rear lambda - pm me if your interested

i put a sports cat on my veccy 2.2 and it threw up the p0420 code within 2-3 weeks of driving, initially i put a simulator on the rear but it still threw up the p0420 code meaning it was the front lambda causing the problems

i took off the simulator and put an ngk rear lambda on and the code dissapeared but i recently replaced the front with a genuine i got off ebay

if i was you and u can afford it then buy a new cat and both lambdas

the front could quite easily be playing up and as a result fudged up your cat m8

we got another member on here called scott [butler] and he replaced both lambdas and i think his problems have gone now

the p0420 code is simply not a case of too much gas passing that sensor, it is about consistency in terms of voltages at any one time when the ECM does the monthly diagnostics check 😛 to ensure your cat is not being fudged

and if you have a crack in your manifold then it needs to be sorted asap as your lambda's will be pissing in the wind, from the rear lambda to the head needs to be sealed otherwise your emissions will be all over the place

Steve_T

Had another code pop up today - P1514, I've searched the site and found a couple of other people who have had the same code.

In my case when you depress the accelerator as far as it will go, say in third gear at 30mph there is hesitation and then a blowing flat sound. Every now and then the car will become lumpy and unwilling to rev, turning the engine off and back on seems to temporarily solve the problem.

I took it to a local garage who read the code (p1514) and they suggested changing the throttle body, going by previous posts this part seems to be reliable and unlikely to be causing the problem. but of course I don't want to totally dismiss the idea.

Once again I'm stuck and need some advice.

Thanks in advance!

MikeS

Since the garage reset the p1514 code it hasn't reappeared, in fact it was quite a suprise to see a different code to the p0420 I've been getting lately. The car becomes lumpy without prior warning, the p1514 code only appeared when the car actually cut out (stalled itself) on my drive.

Is changing the TB over something I could do myself bearing in mind that havne't got a mechnical background?

sorry deleted the wrong post as i had duplicated mine

MikeS

relates the the circuit concerning the TB

wouldnt hurt getting a spare tb just to try

does she become lumpy after the ecu light kicks in [limp mode]

when i had a blocked pre cat p151* range of ecu codes did appear and the lumpy unwillingness to rev came when it went into limp mode

not every problem is a blocked cat so get yourself a second hand tb for 20 quid and try it, if the flap on the tb is failing then the sound your getting might be lack of air

vocky

it might be a bad connection of the plugs behind the water coolant tank, you could spray a bit of wd40 on the contacts and then reconnect them.

certainly the ngk lambdas are good, the cheap lambdas are exactly that - cheap

Steve_T

I've been out to check the plugs fixed to the coolant tank and like most things on the car are impossible to reach unless you've got double jointed hands 😃 I'll keep at it though, thanks for the advise.

Steve_T

I've cleaned the connections on the coolant tank and the top half of the throttle body (Tried and failed to remove it completely, couldn't get one of the bolts out) to no avail. I'm still getting a rattling noise when I rev the engine when stationary which leads me to believe that the cat has packed in, so I'm gonna price up a new one.

MikeS

you read my pre cat problems

edbutler

Is the TB ported/polished? How is the car at idle - 750rpm, Responsive and smooth? Mine seemed to do some of what you described with an Inlet manifold air leak. I had the 1514 code, but not the other code however... Maybe worth a look?

Steve_T

edbutler said:
Is the TB ported/polished? How is the car at idle - 750rpm, Responsive and smooth? Mine seemed to do some of what you described with an Inlet manifold air leak. I had the 1514 code, but not the other code however... Maybe worth a look?

The car idles at around 1200rpm when first turned on then eventually settles down to 750rpm after a minute or so.

MikeS

thats about right

does she start playing up after revving her

Steve_T

Its once you start driving, you put your foot down and the car doesn't rev/won't go above 2000rpm, so obviously no power. Turning the engine off and back on again just repeats the process.

To answer a previous question, the TB hasn't been polished and ported.

Steve_T

Mike S - I've just seen your stickie at the top of this page about the pre cat blocking the main cat, the picture has been removed, any chance you've still got it handy?

MikeS

i deleted it i think m8

give me 10 mins to sort out the photos and check the thread again

MikeS

oki it is up now m8

a friend who does the Q&A for TV added it in an issue about 4 months ago

Sjdickso

I have also had the P0420 code come up on mine, what code reader are you using? I am sure my issue keeps popping up due to the 200 cpi cat. I may get a new front sensor as the rear one was replaced not so long ago.

Steve_T

I'm using a code reader bought from 'talktomycar.com'. I've got a standard cat at the moment but I'm having a Chris Turret 200 cell cat fitted on Monday as I think the standard cat is blocked, now I'm getting a P1514 code and the car isn't drivable.

MikeS

it is pointing towards throttle body imo

Steve_T

If the new CAT doesn't sort out my problems then a new throttle body is next on the list, I've already taken it off to clean it.