saab 93 150BHP EGR Valve

24 Apr 2008
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UK, Wittering, West Sussex
United Kingdom
you helped me recently with a vauxhall egr valve and i received advice about a flap controlled by a vacuum valve and that was sticking and WD40 has fixed it


I have a 93 Saab 150 BHP Engine and the engine light often stays on when starting and the code is the gas recirculating error P0400 - I have a code reader , which also will read the engine running

I have removed and cleaned out the EGR valve (square onto the engine and ellipse onto the pipe ) and it was very full of carbon

fitted new gaskets

however the light still stays on - ONLY when starting and maybe after 10 or more starts - if you dont wait for the check to finish it will come on more frequently
when the light is on it run fine, infact since cleaning out its running much better.

I took the EGR valve off and took the solenoid off and cleaned all that out and made sure the valve moved and cleaned all the seating for the valve

same issue 10 or more starts and it comes on again

following the advice on WD40 on the vauxhall

I took the EGR off again yesterday and used WD40 on the solenoid pin and was moving slighty clicking

Also WD40 on the main valve moving parts, which was quite stiff and so again WD4 on the mechanism and all the two valve part and the spring and it freed up immensely - so i was sure that had resolved the issue.

But after 5 starts , tonight the light stayed on again at startup - in fact it just does not go out from turning the ignition and starting

resetting the code - it will now work for the next few days (about 10 starts)

the car runs really well
NO smoke out the exhaust
revs upto 4500 with no issues
pulls really well
been on a comple of 100 mile trips and it runs great

So i wonder what else it may be - like the vauxhall a paddle somewhere needed some WD40 on a valve - or something else cleaned out.

I have been on another forum when this first started , and advised that it maybe the ECU , which is under the front wheel panel

I have in the past had a steering lock warning come up - that has happened twice in the last 2 years 10,000 miles.

any advice welcome, as i do not have the funds to put in a garage and would like to get resolved myself if possible.
And certainly could not afford a new ECU - which i suspect would be in 4 figures

As MOT due in Sept , i don't want the light to come on when they start the car and fail the test :( :(

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id start by removing the egr valve and examining the inlet manifold passages for signs of further build up, paying particular attention to any electrical sensors that maybe in the manifold (boost pressure sensor/map sensor etc) that may be covered in crud too.
Thanks for the prompt reply

id start by removing the egr valve and examining the inlet manifold passages for signs of further build up

Thanks but none of that inlet manifold is showing - the EGR valve just screws onto the side of the engine

whats involved in getting to the
inlet manifold passages for signs of further build up ... boost pressure sensor/map sensor etc
The egr valve mounts in the inlet manifold, its not really a job for a non car savvy person to be honest. Same goes for the sensors, its just a matter of finding them removing and cleaning.
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Thanks , i have posted there - Originally for the EGR , I posted on the saab forums , but as this forum solved my vauxhall issue - i thought i would start here
no reply from UKsaabs :(

so @ the weekend , I cleaned the MAP and MAF sensors

2 days later light comes on - only when starting

I removed the throttle body and cleaned that up - in an awful state
also the pipe to the trottle body - took that off and it was full of muck - so cleaned that out too

Also the inlet around the where the TB connects was very clogged and all round the spiral sections , absolutely full of crap

cleaned all that all and now i see how the egr valve works - so that all clear

put everything back 7hours later

car low revs very lumpy
took for a run
low revs very low performance - no pull
then engine light on
now i get a
P2279 - intake air system leak

so no idea what i have caused now

will take it all off again tomorrow and see if i caused any issues?

live readings are
Code is P2279 Intake Air System leak

Run the live data -

MAP 103Kpa
MAF 9.72g/s

MAP 139 Kpa
MAF 54 g/s

reset the code and the live data results are the same
Check all pipes from the turbo to the intercooler etc for splits or disconnection.....I'm pretty sure the turbo isn't working here.
John :)

your link talks about EGR valve again
Its either a defective EGR Valve or a split charge air hose. Most common splits are the hose onto the Throttle Body

I had a good look around and could not find anything lose on any hoses

tool the TB Hose off again and had a good look and made sure it went back on really tight on the clamps

took the TB off again and put the old gasket backon , just in case

and checked all i could

no change - drive around the block an up comes the light

so instead of having a light that came on when starting and made no difference to performance

I now have a car that not drivable as it goes into limp mode - really really unhappy - thought i had it fixed

need to sleep on it and see what i can do in the morning - I clearly have mucked something up

cleaned MAP and MAF sensor on saturday and improved the light did not come on as much
then travelled 200miles on monday and light came on

so hence my stripdown today

very unhappy bunny right now.......
Does you radio have a code ?

If not then disconnect the battery for ½ hour

Then try again. (Works on Hondas !!)
took the battery off for 15 mins

went for a drive - still did seem to pull great , not as bad as before , but drove about 5 times further than before and no light this time

I assume the ECU is now relearning all the new settings

all that appears to happen is the stereo reset and rescanned and the satnav changes to metric - , which the sat nav did on a service anyway

so tomorrow, I guess a longer driver test

The MAF sensor seems OK - as the throttle is open when switched off - i guess that goes to baro pressure and looking on the web thats about 100Kpa

I also had the code reader on live data - and the sensors seemed to be changing as i drove - no idea if correct though

i loosened all the band on the system and retightened them all - all the MAF and the TB
had a neighbour come over and got them to look in every joint - just in case i was missing the same thing
pushed every plug

but as i say - i it did not have a great lot of power pulling away to start in 1st and 2nd
and seemed to get better after a few miles - i probably did about 8 miles
Yes 100Kpa = Atmospheric pressure = 1Bar

So you have virtually no boost at tick over (0.03bar) as you would expect. building to 0.39bar at 4000RPM which doesn't sound brilliant, but I don't know the spec. Usually about 0.7 to 0.9Bar = max boost
no , i dont know

But i will take the battery out again tomorrow and allow to idel for 15mins and learn the idle
and see what happens once its learnt and dealt with all the air in there from taking it apart

the turbo kicks in at 2500/3000 revs and i then feel a surge of power

i have a look at the readings while driving - as those where not unload load - just stationary

what sort of figures would you expect ?
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