Should i put 1200 dollars into this car with 260000km for a new front and rear catalatic converters. P.S I only paid 200 for the car a year ago.

Sounds like a wire connection may have gotten pulled when the alternator was replaced. Some vehicles have coil packs that could have got wires disturbed. Dont know what your vehicle is since you didn't put year make or model.

Filling the engine oil above the maximum fill mark on the dipstick can and will cause damage to the catalytic converter. If you have a check engine light on scan and look for a code that indicates a problem with the catalyst. If there is a code indicating a problem with the catalyst this is your catalytic converter. You can get an aftermarket converter from about any parts store for around $200 but it will probably only last about a year. I recommend a VW Genuine converter and they are about $500 but they last much longer than the cheaper aftermarket converters. Before you run out and buy a converter, make sure that this is the problem before you spend a lot of money only to have the same problem. 1 way to verify it is to remove the converter and install a section of pipe where the converter was and see if you still have a power loss. I do not recommend driving the car this way for a long period, just long enough to test it and verify it or further damage may result. Hope this helps.

I can answer the first question. The year of your car will run without the cataltic converters and not affect the performance or fuel milage. Your ECM is not that sophisticated. You can call a parts store and they can tell you where the ECM is located

I guess that depends on what seal? the header seal from the manifold will cost you a couple hundred eaily. The catalatic converter to exaust seal (or donut) 50-75 dollars.

i would say about $600.00 dollars, also alot of places wont warranty it because it may leak due to high mileage and worn crank, this is costly because the trany needs to be removed in order to do rear main seal. hope this helps.

I would say probabley a clogged catalatic converter need to put on a new one.

check the catalatic converter since the truck has been sitting for several years it is not uncommon for mice to make the exhaust system there new homes. depending on where you live if you have emission checks or not you could cut the cat off the truck and run a flex hose in place of it. but i warn you it is not the most leagle thing to do but it wont matter if your state dosent have emission laws. but if you take it to an exhaust shop after this modification they will require you to put a catalatic converter back on to the truck. i hope this info helps you. and please rate my solution
Thanks

have you ck the catalatic converter it could be plug up?go to a muffler shop an have them test the catalatic converter the problem mightnot be youre transmission.let me know

hey if you truely think it is your egr valve unhook it and if that is the problem then when it is unhooked it should run better and the codes should not come up. hey if you cahnged the 1 o2 sensor and not the other you probably made the code for the one u repalced come up again. i would recommened that you change both of the o2 sensors at the same time. try checking if your catalatic convert is plugged. how you do this is take a dollar bill and hold it at the end of your tail pipe while it is idleing and if the dollar bill stays still you have a plugged catalatic converter.