Any pointers/advice appreciated please - poorly starting 997

[Mac68]

Apologies for the long post. I need some pointers or advice please. I've recently had some "engine out" work completed a reputable garage. The works were new x-over pipes, rear coolant pipes and various items whilst I was at it, LTT, tandem pump, plugs, coil packs, AC condeners, TIP seviced, full service (filters) and new brake fluid, rear discs and pads.

Before pickup the garage rang to say it's throwing a Lamba error, I forget which one and asked them to replace it. After replacement the other one, on the same exhaust, errored too. Long story short the garage you can drive it and pop to have latest erroring one replaced at my convenience. The car was running fine for a couple of weeks until this earlier this week I had an issue starting it when cold. It started intially but seemed to drop it's revs really quickly from 1200ish to 800ish and then almost immediately to 600 at which point it was running really lumpy and wouldn't rev back up to 1000 and then proceeded to cut out. I tried a start it a couple of times and it wouldn't start and then the battery was flattened. I had been doing a lot of short trips and moving it in and out of the garage, whilst I worked on the garage.

I "assumed" the battery was kapout and that somehow the ECU wouldn't allow the car to run smoothly or properly without a decent battery, even after starting. I checked and the battery was nearly five years so I replaced it with Bosch S5 85.

The problem persists but only the first time I start the car for a "while", but I'm not using it enough to determine what a "while" is at the moment. It's not a daily driver.

One other thing, the garage fitted my used but fixed up (about to be Gundo'd) mufflers. The previous mufflers were shot and the joints and flexi joints had gone. I figured it was a good opportunity to get the old ones off and the new ones fitted with decent SS bolts etc.

Any pointers of what I should be researching would be really appreciated.

I have ICarsoft PORii OBD reader but don't really know what to look at.

The garage have said they'll have a look but I can't make it back for a while.

Thanks in advance.

 

[deMort]

Can you connect the OBD reader .. look for dme or engine ecu then look at the fault codes and post them here please .

Its a difficult one to call as you have had a lot of work done .. it had issues at the time and now i assume weeks later it has another issue ..

These could be connected or totally different issues ..

Anything to do with exhaust work can kill the lambda sensors .. its a possible and it sounds like you had 2 replaced .. this could have been post cat ones if there was no running issues .

You have the possibility of damaged pre cat sensors atm ..

You have the possibility of a Maf sensor fault from the description you gave ..

You have the possibility of a high lift solenoid sticking .. this will cause uneven running at low rpm and due to the lack of use im leaning towards this to be honest on one or the other banks .

A fault code readout of the Dme and we will have something to work with as for now .. its a total guess i'm afraid .

 

[Mac68]

Thanks deMOrt, I appreciate it.

I'll pop the reader on tomorrow and report back From memory there's mention of an O2 and HO2 sensor.

Definitely only one sensor replaces so far. On the receipt it's listed as a Lambda but I forget which one was replaced pre or post cat.
The garage have been good, they said pop it back and they'll fit the other FOC, which they don't need to do.

The car didn't have any issues before the work, it started and ran OK.

Thanks.

 

[Mac68]

I've checked and I have two codes, both I think are related to the failed O2 Sensor that I know about.

P0050 and P01534.

According to the below
https://www.pelicanparts.com/techar...ors/19-FUEL-Replacing_Your_Oxygen_Sensors.htm
a faulty sensor can cause the issues I'm experiencing :dont know: but what's puzzling me is the car ran fine for a few weeks with the CEL.

Is it possible it's related to the type of driving I've been doing as initially, I was on faster roads and recently it's been more local roads?

Thanks

 

[deMort]

The codes both relate to bank 2 pre cat lambda sensor .. one being the heater circuit the other an out of limit issue which could also be down to the heater circuit .

This would normally be a new lambda sensor .

This fault though .. it doesn't fit with your description of what the car is doing .. if the car knows a sensor is unreliable then it ignores the sensor data and works off of other sensors .

The start point would be a new sensor .. it may fix the issue but im dubious atm .. with no misfire codes then that kind of leans away from a high lift solenoid issue ..

New sensor .. the garage will investigate and if needed we can go from there .. to be honest though i would expect the garage to find the issue if its not this and again i don't think it is .

 

[Mac68]

Cheers again deMort.

I'll wait till I've had the Lamba sensor replaced in a couple of weeks and see what happens after that.

Thanks for your input.