Just been to start the car to go out - started easily from cold, but, sounded like a tractor and hadn't even got the power to reverse off my flat drive without trying to stall !
I am now at the point where I am not prepared to try to drive it until this issue is solved, so here is where we are at:-
full history since problems started:-
whilst powering hard up a steep hill car began "missfiring", cleared itself, but then went into Limp Mode with resultant loss of power and EML illuminated on dash. Parked up, turned off, restarted 30mins later, Limp Mode cleared it self, car ran fine, EML light stayed on.
Car into garage for service and to have fault codes read. Garage performed service, but, could not find air filter on car and could not find one listed on their parts databse - so they assumed car was not fitted with one (?!!!) so not changed. Fault code found - P0237 "Turbo/Supercharger Boost Sensor 'A' Circuit low" . Advised Tyres need replacing, Cambelt change due (5 years), Tracking needs attention. Car still running fine. Rang local motor factors to order air filter - had one in stock ! Purchased and decided to find different garage !
Whilst overtaking at 60mph in 4th gear at about 3500 rpm, car starts "missfiring", EML comes on, car goes into Limp Mode. Take to nearest garage for check (different garage, different town) - unable to get their diagnostic machine to communicate with ECU. Garage fits air filter for me. Arrange to return in two days for more thorough ecu check. Car now running fine again.
Return to garage, diagnostics eventually communicate with ecu - Fault codes as follows:
P0237 "Turbo/Supercharger Boost Sensor 'A' Circuit low"
U1601 "Key/Transponder recognition fault"
P0504 "Brake light Switch Fault"
Garage reset ecu - take for test drive, car now even worse than ever - no boost below 3500rpm in 1st gear, but, took off like a banshee in 2nd ! Tried with MAF disconnected - unknown result, I wasnt in the car that time. Fault appeared to clear itself again - took car away with intention of doing some research and return with ideas.
Following research, I decided to fit new battery as car is 5 years old and still running original factory fitted battery - apparrently, low battery voltage can cause problems with erratic ecu funtioning. New battery fitted, take for test drive - feels a lot better, but, still not as it should. Then, whilst driving up a hill at 40-50mph in 3rd gear @ about 3000 rpm, car "misses" then a Thump, followed by a second or two of rattling, during which engine almost stalled and EML came on. Dipped clutch and revved engine - all settled down- no rattling or nasty noises, but, no power. Limped the 300 yards or so to nearest layby. Left car to tick over, no unusual noises noted, but, still no power. Decided to risk limping home - car ran and sounded fine, but little power.
Removed and cleaned EGR valve and 'Throttle body'. Throttle body flap had very little carbon deposits, flap moves freely and returns with ease when moved by hand. EGR valve cleaned and washed out with EGR cleaner - noted a stripped thread on the lower left hand bolt to inlet manifold. ERG valve not tested as not sure how to, and not stripped down, only removed and chamber cleaned out. Unknown if functioning correctly.
Symptoms as of yesterday - started fine from cold - appeared to run as normal for few minutes, but, as engine temp increased power seemed to fall off, until, at indicated normal running temperature, engine seemed to have no power whatsoever and requires increased revs to pull away from standstill without stalling.
Advised to check vac hose to wastegate as wastegate sounds like it is constantly venting.
This morning, whilst starting from cold, car started easily, but, sounded very rough, like a tractor, with no power to pull away from standstill without lots of revs.