94 530i lambda issue

[Charliexx95]

Hi guys so I bought a 94 530i from a auction car was and still is running rough had various o2 sensors and lambda codes and replaced the 02 sensors. Well the o2 sensors code went out but both lambda codes remain there I resealed the whole intake manifold with new gaskets bought meylen pvc and after car ran a bit better but threw alot of smoke from the tail pipe. The 1222 code went out but the code 1213 code still reappears every time the cars gets to normal temp. So I bought a OEM bmw PCV and redid intake manifold gaskets and check engine still lights up still throws alot of smoke from the tailpipes and when driving it feel like If the car is towing something big like it's just super slow plus when hitting the accelerator it just takes it time to go up on mph... I'm stump because I did replace alot of parts with new ones and still cant get this damn lean/rich code out any help would be appreciated

Check engine light code:
1213

Parts I've replaced :
Ignition coils
Fuel regulator
Spark plugs
Maf
O2 sensors
Intake gasket
OEM pvc
Intake boot
Temp sensor
CPS
Hose from regulator to PVC
Valve cover
Valve cover grommets
3 fuel injectors
All fuel injectors orings
Checked for vacuum leaks none (carb cleaner method)
Checked all wiring all checked good

Also when I let the engine running for like 15 minutes it tends to throw 1212 code which is really weird because o2 sensors dont even have 10 miles on them
car has 280k miles and I feel like it could be a bad cat or maybe a nikasel issue

[ross1]

Quit throwing parts at it and do some diagnostics. P codes don't mean "replace X"
What is the fuel pressure? Does it crank a long time to start?

[darren1284]

I recall having a similar problem. 1st changed the O2 sensor because it was due to be replaced. Still pulled up O2 and lambda sensor codes.

Took it to an independent shop and he diagnosed a bad MAF and blamed it on the K&N filter I had. It still had the same codes. I was also getting more than normal exhaust smoke and the engine was hesitating.

There were no obvious signs of a head gasket failure like mayonaise deposits on the engine oil cap or discolored coolant or oil, but a compression test confirmed that there was a failed head gasket.

Once I got that resolved, there were no more codes and the engine runs great. I have to question the bad MAF being caused by the K & N filter diagnosis now, though. That MAF may have been perfectly fine.

[ross1]

I recall having a similar problem. 1st changed the O2 sensor because it was due to be replaced. Still pulled up O2 and lambda sensor codes.

Took it to an independent shop and he diagnosed a bad MAF and blamed it on the K&N filter I had. It still had the same codes. I was also getting more than normal exhaust smoke and the engine was hesitating.

There were no obvious signs of a head gasket failure like mayonaise deposits on the engine oil cap or discolored coolant or oil, but a compression test confirmed that there was a failed head gasket.

Once I got that resolved, there were no more codes and the engine runs great. I have to question the bad MAF being caused by the K & N filter diagnosis now, though. That MAF may have been perfectly fine.
I'm gonna guess you also had some misfiring with the failed HG. Water in the oil is only one manifestation with a particular failure mode.
The K&N's oil mist does pollute the MAFs hot wire, perhaps yours was still okay but those are NG for the MAF.

[darren1284]

I do think mine was overheating too- that was a key piece of information.

[E34 Lives]

Looks like you have a major vacuum leak, if you have replaced engine various gaskets and pvc plate and have checked for leaks and found none on the engine, the next logical place to check is the brake booster, this is one of the major vacuum leak area that is missed when troubleshooting, and will not show up on a smoke test. You can try pumping brake when engine is running in drive .... do this until you get rough idle or when engine cuts out ...... then you have found your engine vacuum leak (there are also other ways to test like removing vacuum hose), but try this first as it is most easiest.

[Charliexx95]

Guys sorry for not adding a update the problem was found and fixed

The problem was that 2 injectors in cylinder 3 and 4 were not working after getting frustrated and all took a day or two to cool off came back with a clear mind and started doing tests all was cleared till I put a screw driver on top of each injector to see if there's any ticking sound and two of them didn't make any sound changed those from my other project car and code disappeared in 15 mins took it to get it registered again and went on a 2 hour drive to get it pass smog which it did thanks for all the help and info much appreciation