RCZ stops responding after heavy traffic

[KMG]

Hi, I have a 2014 156 RCZ with only 38k on the clock. Shortly after getting it, I was stuck in a massive slow moving traffic jam in the winter for an hour, and when it cleared, pushing down the throttle basically did nothing, the car just slowly picked up speed. This lasted for 6 months, then three days after a full service at Peugeot, I just thought 'sod it', and floored it in first, away from some traffic lights. It was like magic, and the car instantly returned to its 'normal' behaviour, ie, press throttle, car flies!
It's been fine for two years, and I've been stuck in similar jams, but in hot weather, and they had no detrimental effect.
Tonight, I was stuck in a slow moving jam for thirty minutes, and at the half way point, I literally felt the car change characteristic, and I could feel that pressing the throttle and letting out the clutch didn't 'move me forward', with the same feeling as it had been doing. When I came out of the other end of the jam, pushing the throttle in 2nd, having moved away from the lights in first, basically had no effect, even pushing all the way to the floor. The car just accelerates slowly, rather than a very quick 'lag', then shooting off rocket-like, as it normally does. The car didn't overheat during the traffic jam, the temperature gauge being in its' normal position, and there are no warning lights, no engine management light, no 'limp mode' indication, no nothing.
Hopefully, the car will be ok after cooling off overnight, or I may have to 'boot' it again to 'reset' it, like last time, but what is causing this weird behaviour?!
Even if it does fix itself, or I manage to, being stuck in a traffic jam for any time, should not result in the car's characteristics changing, to the effect that the car just gradually picks up speed even with your foot down. It's like pressing the throttle gives you the revs, but there's no 'kick', if you get my meaning.
I obviously have to find the reason behind this, as I can't put up with this strange behaviour everytime I get stuck in a traffic jam! Car had a full service last February, so I can't imagine anything being 'clogged' etc.
Is it possible that this could be caused by an overheated/blocked catalytic converter, as has been suggested?

Any ideas????!!!!!

Regards,
Kevin

 

[Pedro]

Scan the car !
Culprits could be Turbo Lag
Fuel pressure issue Aux or Main fuel pump ?
Vac leak etc

 

[KMG]

Scan the car !
Culprits could be Turbo Lag
Fuel pressure issue Aux or Main fuel pump ?
Vac leak etc

Ok, why would this behaviour occur only after sitting in a very slow moving traffic jam for a prolonged period? Having a service in a few weeks and then I'll get it in to Peugeot for a scan (Diagnostic scan?). Obviously a scan would be best done when in this 'odd' state, but I guess a diagnostic would find anything dodgy. Fingers crossed!

 

[Pedro]

If the engine loses power its for a specific reason sensors fail over time so do plugs & coil packs timing chains throttle position sensors & issues with fuel pressure delivery as well as Turbo boost failures these all contribute over time to serious loss of power it may be an intermittent fault which can be harder to track down also when you say a service this will be normally be an oil change & air filter plus a diagnostic scan if required which may even not prove anything I can only suggest you purchase a cheap scan tool & when you get stuck in traffic plug it into the cars OBD port to try & record any live data as that will almost certainly tell you why the car is behaving as it does & should show or point to any faults

 

[KMG]

If the engine loses power its for a specific reason sensors fail over time so do plugs & coil packs timing chains throttle position sensors & issues with fuel pressure delivery as well as Turbo boost failures these all contribute over time to serious loss of power it may be an intermittent fault which can be harder to track down also when you say a service this will be normally be an oil change & air filter plus a diagnostic scan if required which may even not prove anything I can only suggest you purchase a cheap scan tool & when you get stuck in traffic plug it into the cars OBD port to try & record any live data as that will almost certainly tell you why the car is behaving as it does & should show or point to any faults

Good news! Took car to mechanic who used obd2 scanner. Found a rich mixture fault code, cleared it, and car back to normal. It's like a miracle. Now car responds immediately to throttle. He suspects that being stuck in heavy traffic somehow caused the EMS to go into some kind of protective mode, causing sluggish acceleration. In for a major service in a couple of weeks so he's going to check everything he can including MAP sensor, fit new filters etc. He also suggested that I buy a cheap obd2 scanner which I definitely will. There are plenty of them on Amazon for around 20 quid. To be honest, I'm guilty of only using the car to pootle to work and back everyday, so it would probably benefit from a good run ocassionally.
Can anyone recommend a budget obd2 scanner that reads and deletes error codes on the RCZ?
Someone told me that error codes come on different 'levels' and sometimes an expensive scanner is required.

Lastly, probably a daft question...does pootling to and from work (10 miles each way), often in the cold and in traffic, actually 'bung up' a car, specically, obviously, an RCZ? Does taking it for a 'good run' occassionally 'to get it nice and warm' actually keep it running better (and possibly avoid my loss of acceleration when stuck in traffic for ages problem)?

 

[Pedro]

Put fresh fuel in & add Red X & take it for a walloping somewhere getting it roasting HOT this should clean any crap hiding in the fuel & exhaust system & the car should respond better as for code readers look for one with the highest reviews but is low priced ?

 

[neilgsxr69]

Yeh it definitely has been going into limp mode, if you have the 156 variant even with the low milage could probably do with an inlet valve clean.
It’s strange that it didn’t throw an EML though

 

[KMG]

Put fresh fuel in & add Red X & take it for a walloping somewhere getting it roasting HOT this should clean any crap hiding in the fuel & exhaust system & the car should respond better as for code readers look for one with the highest reviews but is low priced ?

Looking at the Autel AL519 as it's mentioned here on this forum so obviously works with the RCZ. About £60. There's also the AL619EU at about £100, but I think the AL519 us probably adequate.
AL519 reviews anyone?

 

[Chillipip]

I had similar on mine which was the TPS. Changed the throttle body toll and it was sorted. I use the thinkdiag with the app and it is brilliant.

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